Singapore's civil aviation authority says it has temporarily banned all Boeing 737 Max planes from entering and leaving the country.
It noted in a statement today that there have been two fatal accidents involving the aircraft in less than five months.
Sunday's deadly crash of an Ethiopian Airlines 737 Max 8 killed all 157 people on board.
The authority said the suspension starting later today will be "reviewed as relevant safety information becomes available".
It was believed to be the first country to ban all versions of the Max planes.
The suspension will affect SilkAir, a regional carrier that's wholly owned by Singapore Airlines. It has six Boeing 737 Max 8 planes.
The authority said that flights to Singapore by China Southern Airlines, Garuda Indonesia, Shandong Airlines and Thai Lion Air will also be affected.
Singapore joins a growing number of airlines that have grounded planes.
Airlines in Ethiopia, China and Indonesia have temporarily grounded their Max 8s, in addition to Caribbean carrier Cayman Airways, Comair in South Africa and Royal Air Maroc in Morocco. Other airlines have issued safety warnings or are conducting inspections.
South Korean transportation authorities are conducting a safety inspection of a local airline that uses the same aircraft involved in the Ethiopian Airlines plane crash that killed 157 people.
An official from low-cost carrier Eastar Jet said today it doesn't have immediate plans to suspend operations of its two Boeing 737 Max 8 planes it uses on routes to Japan and Thailand.
He said it will wait for the inspection's outcome. No other South Korean carriers operate the plane.
South Korea's Transportation Ministry says the inspection on Eastar began hours after the Ethiopian Airlines crash.
The Eastar official says government officials are reviewing Eastar's flight operation manuals and the planes' machinery and software. She said the airline was getting calls from worried customers, but no cancellations.
Fiji Airways says it will continue flying its two Boeing 737 Max 8 planes to Pacific destinations.
Fiji's national carrier said in a statement today it's following the situation closely and has full confidence in the airworthiness of its fleet. The airline says it mainly uses the Max 8 planes on routes connecting Fiji, Australia and New Zealand.
New Zealand's Civil Aviation Authority said Fiji Airways was the only carrier landing Max 8 planes in New Zealand and it could continue doing so.
India's Jet Airways says it has grounded its five Boeing 737 Max 8 aircraft after the Ethiopia crash.
The airline said it is not flying any of the 737 Max planes in its fleet and is "in contact with the manufacturer."
On Monday, India's aviation watchdog said it ordered a safety assessment of the aircraft. It also issued safety instructions for flying Boeing 737 Max 8 aircraft.
The directions call for the pilot-in-command to have at least 1000 hours of flying experience and the co-pilot to have 500 hours on Boeing 737 NG type aircraft.
Indian airline SpiceJet also has Boeing 737 Max 8 aircraft, but it's unclear if those planes are grounded. Calls and emails to the company were unanswered Tuesday.
Brazil's Gol Airlines is suspending the use of its 121 Boeing 737 Max 8 aircraft following the deadly Ethiopian Airlines crash involving the same airplane.
The company said on Monday night that as of 8pm local time it would be temporarily stopping the commercial use of the airplanes.
The statement says Gol is fully confident in Boeing's safety operations and it is following updates about the investigation into the 737 Max 8 in order to return the aircraft to use as soon as possible.
Gol says that since it started using the Boeing 737 Max 8 last June, the aircraft have made nearly 3,000 flights with "total security and efficiency."
The Mexican airline Aeromexico says it is suspending flights with its six Boeing 737 Max 8 jetliners following the Ethiopia crash.
The company says it trusts "fully"in the safety of its fleet but adds that the grounding has been ordered to ensure "the safety of its operations and the peace of mind of its customers."
A statement issued Monday evening says the airline is in communication with Boeing as well as aviation authorities about the plane model. It says other planes will take over the flights usually flown by its Max 8 jets.
In the United States, Transportation Secretary Elaine Chao said her department was monitoring developments.
The Federal Aviation Administration noted the investigation into the crash had just begun and it has not yet drawn similarities between the Indonesia and Ethiopia crashes.
The FAA says it expects Boeing will soon complete improvements to an automated anti-stall system that is suspected of contributing to the deadly Indonesia crash of a Boeing 737 Max 8 in October.
The FAA said Monday that Boeing will also update training requirements and flight crew manuals related to the system.
The system automatically points the plane's nose down if sensors indicate the plane could be in danger of losing lift, or stalling. Sensors on the plane operated by Indonesia's Lion Air gave out faulty readings on its last four flights.
On the fatal October flight that killed 189 people, pilots apparently struggled in vain to fight against the automated nose-down commands.
The FAA tried to discourage comparisons between the Lion Air crash and Sunday's deadly crash of an Ethiopian Airlines 737 Max 8. Both performed erratically shortly after takeoff, then went into nosedives. Weather did not appear to be a factor in either one.
"External reports are drawing similarities between (the Ethiopian) accident and the Lion Air Flight 610 accident," the FAA said. "However, this investigation has just begun and to date we have not been provided data to draw any conclusions or take any actions."
State-run carrier Oman Air says it is in close contact with Boeing after the crash of an Ethiopian jetliner, the same model that it uses widely.
Oman Air tweeted Monday that is talking to Boeing "to understand if there are any implications"for other airlines operating Boeing 737 Max 8 aircraft.
It added: "Oman Air's primary and overriding consideration is the safety and well-being of its staff and guests."
Oman Air operates five Boeing 737 Max 8 aircraft. Oman is a sultanate on the eastern edge of the Arabian Peninsula.
Indonesia has grounded Boeing 737 Max 8 planes for inspections following the Ethiopian Airlines crash, the second for the new aircraft since October.
Director General of Air Transportation Polana B. Pramesti said the grounding was taken to ensure flight safety in Indonesia. He said the inspections will ensure the planes are airworthy.
There are currently 11 Max 8 planes operated by airlines in Indonesia including 10 by Lion Air and 1 by national carrier Garuda.
A spokesman says Ethiopian Airlines has grounded all its Boeing 737 Max 8 aircraft as a safety precaution.
Asrat Begashaw said Monday that although it is not yet known what caused the crash on Sunday, the airline decided to ground its remaining four 737 Max 8 planes until further notice as "an extra safety precaution." Ethiopian Airlines was using five new 737 Max 8 planes and was awaiting delivery of 25 more.
Begashaw said searching and digging to uncover body parts and aircraft debris will continue. He said forensic experts from Israel have arrived in Ethiopia to help with the investigation.
The Middle Eastern budget carrier FlyDubai says it is in touch with Boeing and "monitoring the situation"regarding its 737 Max 8 aircraft, but has faith in its planes' airworthiness following an Ethiopian Airlines crash involving the model.
FlyDubai operates 11 Boeing 737 Max 8 and two Boeing Max 9 jetliners. The Dubai government-owned airline said in emailed statements Monday that it "went through a rigorous process"to choose the right aircraft for its operations and noted that it adheres to all regulations regarding its planes.
It says it remains "confident in the airworthiness of our fleet."
China's Civil Aviation Administration said in a statement it would notify airlines as to when they could resume flying the jets after contacting Boeing and the US Federal Aviation Administration (FAA) to ensure flight safety.
"Given that two accidents both involved newly delivered Boeing 737-8 planes and happened during take-off phase, they have some degree of similarity," the administration has said.
Cayman Airways says it is temporarily grounding the two Boeing 737 Max 8 aircraft it operates in the wake of the Ethiopian Airlines crash.
The Caribbean carrier said the grounding would take effect Monday.
While he acknowledged the cause of the Ethiopian crash was unclear, airline President and CEO Fabian Whorms said the airline was taking the step because of its "commitment to putting the safety of our passengers and crew first."
He said the move would lead to scheduling changes as the carrier copes with aircraft shortages.
Cayman received its first Max 8 in November and its second just this month.
The airline is the flag carrier of the Cayman Islands, a British Overseas Territory.