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Authorities at the Manchester Arena believe a "nail bomb" is responsible for much of the carnage, including 22 deaths, at an Ariana Grande concert. Witnesses have reported seeing nuts and other shrapnel around the scene.
Despite authorities not giving a clear indication of what exactly was used in the attack, witnesses and fans have reported wounds consistent with such a device in the Manchester attack. So gruesome was the aftermath, body parts were reportedly scattered through the carnage.
TMZ reports "the explosive device was a nail bomb in a backpack and it might have been a suicide mission".
The publication said it appeared "the bomber was waiting around the exit area as people were streaming out of the building".
So popular are these types of bombs they have been used in a variety of attacks across the world, including the Boston Marathon bombings, St Petersburg, Brussels, West Java, and New York City terror attacks along with attempts in Germany.
Additionally, an Islamic State terrorist taught a Melbourne teenager how to make a pressure cooker bomb and urged him to plot an attack on the city in 2015.
Counter IED Expert Jeff Parks told CNN the explosive devices first came onto the scene in the early-2000s in Iraq, claiming it was a "very common appliance in the Middle East" and "very handy to place a large amount of explosives and shrapnel".
"It was definitely a bomb, the whole building shook. Body parts were everywhere, a torso, an ear. It was the worst thing I have ever seen. Bodies were everywhere," a woman in Manchester, identified only as Emma, told BBC Radio.
One victim's injuries in the immediate aftermath of the Ariana Grande concert were posted to Twitter with what appears to be blood dripping from their legs.
Others said they were "covered in people's blood, skin".
The bombs, usually described as "pressure cooker bombs" are packed with shrapnel including nails, ball bearings and screws to cause the most severe impact on the victims.
"The way a pressure cooker works is it creates a seal, pressure will build," one bomb expert told PBS NewsHour in 2013.
"If we put materials that create a lot of gas and heat very quickly the pressure will build up so fast that the pressure can't contain it and it will burst open and explode, throwing shrapnel all over into the crowd."
Such devices were used in the Boston bombing attacks and the terror attacks in Brussels.
In Boston, the bombers hid the bombs inside a nylon backpack while the device was triggered by a battery operated timer.
The evidence suggested ball bearings and nails were placed around the explosive, sending small projectiles towards spectators, causing injuries to the lower body.
The force of the blast was so powerful, it sent the lid of the pressure cooker onto the roof of an adjacent building.
"These bombs contained small metallic fragments more consistent with pellets and other small pieces of metal, but also spiked points that resembled nails without heads," George Velmahos, head of emergency medicine at Massachusetts General Hospital, said at the time.
The two bombs, which exploded 13 seconds and about 100 metres apart, sprayed the shrapnel into the crowd of thousands of people lining Boylston Street to watch the runners of the famous race cross the finish line.
Three people were killed and at least 180 injured. The dead and injured were aged between two and 71 and included nine children.
In New York, Ahmad Rahami, a naturalised United States citizen of Afghan birth, was identified with the help of a mobile phone left behind with an unexploded pressure cooker found near the site of a bomb blast.
He is believed to be the same man seen in black and white surveillance video taken at the site the bombing in September last year in the Chelsea neighbourhood of Manhattan which injured 29 people.
Police also believe Rahami was behind a pipe bomb that exploded in a trash can on the route of a Marine Corps run in New Jersey.