New York explosion 'intentional', but not terrorism: official

• An explosion has occurred at 8.30pm (NYT), blowing out lower windows of a multi-story residential building in Manhattan
• At least 29 people have been injured
• The injures are significant but not life-threatening. One is in a serious condition.
• Authorities believe it is an "intentional act", but not terrorism
• Reports the explosion occurred in or near a dumpster
• Multiple emergency services at the scene which is cordoned off
• Investigations into the cause still underway but gas has been ruled out
• Law enforcement source tells AP second device appeared to be a pressure cooker attached to wiring and a cellphone

An explosion in a crowded Manhattan neighborhood has left 29 people injured, and authorities said a second nearby site was also being investigated.

Mayor Bill de Blasio called the blast an "intentional act," but said there was no terrorist connection.

"Tonight, New York City experienced a very bad incident," de Blasio said at a news conference near the scene in Chelsea.

"We have no credible and specific threat at this moment. "

De Blasio said the blast was "an intentional act" and tried to calm any fears among nervous New Yorkers, saying the explosion had no terrorist connection and wasn't related to a pipe bomb explosion earlier Saturday in New Jersey at a charity run.

A law enforcement official told The Associated Press that a second device that officers were investigating four blocks from the scene appeared to be a pressure cooker attached to wiring and a cellphone.

The source, speaking on condition of anonymity because the person was not authorised to speak about an ongoing investigation, said the device was found inside a plastic bag on West 27th Street.

A law enforcement official told The Associated Press that the explosion appears to have come from a construction toolbox in front of a building. The official spoke on condition of anonymity because the person wasn't authorized to speak about an ongoing investigation. New York officials said the incident was not due to a gas leak.

The blast happened on West 23rd street, in front of a residence for the blind, near a major thoroughfare with many restaurants and a Trader Joe's supermarket.

Witnesses say the explosion at about 8:30 p.m. blew out the windows of businesses and scattered debris in the area. Officials said no evacuations were necessary.

Police spokesman J. Peter Donald said several people were taken to hospitals with injuries.

One of the injured suffered a puncture wound that was considered serious. Officials said the other injuries were minor, described as scrapes and bruises.

#Update re: Explosion (photo) pic.twitter.com/AtqllF3JEZ

— NYPDCounterterrorism (@NYPDCT) September 18, 2016

Donald tweeted a warning to residents near the second site that officials are investigating, saying: "As a precautionary measure, we are asking residents who live on West 27th Street between 6th and 7th Avenues in Manhattan to stay away from windows facing 27th Street ..."

A number of New York City subway routes were affected by the earlier explosion.Chris Gonzalez, visiting from Dallas, was having dinner with friends at a restaurant in the area.

"We felt it, we heard it, the restaurant went real quiet, the 26-year-old Gonzalez said. "It wasn't like jolting or anything, everyone just went quiet."

Rudy Alcide, a bouncer at Vanity Nightclub at 21st Street and 6th Avenue, said he, at first, thought something large had fallen.

"It was an extremely loud noise, everything was shaking, the windows were shaking, it was crazy," he said. "It was extremely loud, almost like thunder, but louder."

Firefighters arrive at the scene of the explosion in Manhattan's Chelsea neighborhood. Photo / AP

The FBI and Homeland Security officials, along with the ATF arson and explosive task force are also at the scene.

The White House said President Barack Obama has been apprised of the explosion in New York City and will be updated as additional information becomes available.

In St. Cloud, Minnesota, police said multiple people were injured at a shopping mall Saturday evening in an attack that possibly involved both a shooting and stabbing.

25 injuries to civilians confirmed at 133 W 23 St #Chelsea. None appear to be life-threatening at this time

— FDNY (@FDNY) September 18, 2016

The suspect was believed to be dead.

Hillary Clinton says she has been briefed "about the bombings in New York and New Jersey and the attack in Minnesota".

She says the nation needs to support its first responders and "pray for the victims".

"We have to let this investigation unfold," she said.

The reports of a possible blast come hours after a pipe bomb exploded in Seaside Park, New Jersey, shortly before thousands of runners participated in a charity 5K race to benefit Marines and sailors. No injuries were reported.

An explosion in a crowded Manhattan neighborhood on Saturday night left 29 people injured, and authorities said a second nearby site was also being investigated.

Mayor Bill de Blasio called the blast an "intentional act," but said there was no terrorist connection.

"Tonight, New York City experienced a very bad incident," de Blasio said at a news conference near the scene in Chelsea.

"We have no credible and specific threat at this moment. "

De Blasio said the blast was "an intentional act" and tried to calm any fears among nervous New Yorkers, saying the explosion had no terrorist connection and wasn't related to a pipe bomb explosion earlier Saturday in New Jersey at a charity run.

A law enforcement official told The Associated Press that a second device that officers were investigating four blocks from the scene appeared to be a pressure cooker attached to wiring and a cellphone.

The source, speaking on condition of anonymity because the person was not authorised to speak about an ongoing investigation, said the device was found inside a plastic bag on West 27th Street.

A law enforcement official told The Associated Press that the explosion appears to have come from a construction toolbox in front of a building. The official spoke on condition of anonymity because the person wasn't authorized to speak about an ongoing investigation. New York officials said the incident was not due to a gas leak.

The blast happened on West 23rd street, in front of a residence for the blind, near a major thoroughfare with many restaurants and a Trader Joe's supermarket.

Witnesses say the explosion at about 8:30 p.m. blew out the windows of businesses and scattered debris in the area. Officials said no evacuations were necessary.

Police spokesman J. Peter Donald said several people were taken to hospitals with injuries.

One of the injured suffered a puncture wound that was considered serious. Officials said the other injuries were minor, described as scrapes and bruises.

Donald tweeted a warning to residents near the second site that officials are investigating, saying: "As a precautionary measure, we are asking residents who live on West 27th Street between 6th and 7th Avenues in Manhattan to stay away from windows facing 27th Street ..."

A number of New York City subway routes were affected by the earlier explosion.Chris Gonzalez, visiting from Dallas, was having dinner with friends at a restaurant in the area.

"We felt it, we heard it, the restaurant went real quiet, the 26-year-old Gonzalez said. "It wasn't like jolting or anything, everyone just went quiet."

Rudy Alcide, a bouncer at Vanity Nightclub at 21st Street and 6th Avenue, said he, at first, thought something large had fallen.

#BREAKING: police dogs searching for secondary device; #FDNY confirms 25 injuries; 24 minor 1 serious. pic.twitter.com/K29leIuufC

— Josh Einiger (@JoshEiniger7) September 18, 2016

"It was an extremely loud noise, everything was shaking, the windows were shaking, it was crazy," he said. "It was extremely loud, almost like thunder, but louder."

The FBI and Homeland Security officials, along with the ATF arson and explosive task force are also at the scene.

The White House said President Barack Obama has been apprised of the explosion in New York City and will be updated as additional information becomes available.

In St. Cloud, Minnesota, police said multiple people were injured at a shopping mall Saturday evening in an attack that possibly involved both a shooting and stabbing.

The suspect was believed to be dead.

Hillary Clinton says she has been briefed "about the bombings in New York and New Jersey and the attack in Minnesota".

She says the nation needs to support its first responders and "pray for the victims".

"We have to let this investigation unfold," she said.

The reports of a possible blast come hours after a pipe bomb exploded in Seaside Park, New Jersey, shortly before thousands of runners participated in a charity 5K race to benefit Marines and sailors. No injuries were reported.

los primeros instantes después de la explosión en la 23 street, chelsea, new york. los policías recién iban llegando pic.twitter.com/MKV3kLsP9E

— oliver (@cabrogoogleao) September 18, 2016

Police arrive on the scene of the explosion in Manhattan's Chelsea. Photo / AP

Witness accounts

A witness said at least three people were seen being taken away from the apparent scene of the blast in ambulances, on Saturday night but the severity of their injuries was not immediately clear.

Prime Minister John Key is headed to New York this weekend for New Zealand's second term at the presidency of the United Nations Security Council.

He is currently in Houston, and will arrive in the city on Monday.

Witness Jakir Aussin, who works at a nearby Dunkin Donuts, described the explosion as a "deafening boom".

"It was a quiet night, and then I heard this deafening boom," Aussin told the New York Post.

"My first thought was, 'Oh god, a bomb,' so I got down on the floor.

"I looked outside and it's all broken glass, car alarms going off - I still don't know what happened."

Two buildings to the east of the facility were being evacuated. No fires have been reported, but multiple emergency vehicles, including ambulances, rushed to the scene.

"It was a quiet night, and then i heard this deafening boom," said Aussin.

"My first thought was, 'Oh god, a bomb,' so I got down on the floor," The Post reported.

"I looked outside and it's all broken glass, car alarms going off - I still don't know what happened."

A police officer escorts an injured man away from the scene on West 23rd Street in New York. Photo / AP

A Reuters witness said at least three people were seen being taken away from the apparent scene of the blast in ambulances, on Saturday night but the severity of their injuries was not yet known.

According to police radio transmissions, the people inside the facility have been initially told to remain inside as police began their investigation.

Tsi Tsi Mallett, who was driving a car on 23rd Street at the time of the explosion, told Reuters: "It was really loud, it hurt my eardrums. My 10-year-old boy was sat in the back seat of the car, and the explosion blew the back window out."

Neha Jain, 24, who lives in the neighbourhood where the blast took place, told Reuters she was sitting in her room watching a movie when she heard a "huge boom" and "everything shook".

"Pictures on my wall fell, the window curtain came flying as if there was a big gush of wind. Then we could smell smoke. Went downstairs to see what happened and firemen immediately told us to go back."

FDNY reports 26 green tag civilians -- that's 26 minor injuries. The bomb squad continues to search for other devices. #Manhattan #BREAKING

— Marc Ambinder (@marcambinder) September 18, 2016

A local journalist, Josh Marshall, said the incident took place in a relatively quiet area with no particular symbolic or political significance.

While it was a major street in Manhattan, it had relatively light foot traffic, he wrote on his blog.

"Because of this I'm not terribly surprised that there seem to be relatively small number of injuries simply because at 8pm or thereabouts there just wouldn't be that many people around."

Marshall also downplayed speculation that it could be an attack on the gay community, following reports that it had taken place in a gay neighbourhood.

"If someone had a beef with the gay community there's nothing symbolic or iconic on that block or really anything particularly interesting at all besides a few barber shops, a deli, a Donkin' Donuts and a pizza place."

Confirmed explosion at 23rd and 6th Manhattan. FDNY and NYPD treating as an IED.

— matt blaze (@mattblaze) September 18, 2016

#Explosion outside our apartment at 23rd and 6th in #newyork. Terrified. Hoping everyone is okay. pic.twitter.com/i3q4cG7aWT

— N∑H∆ (@nnehajainn) September 18, 2016