Britain's aviation authority is banning all commercial Boeing 737 MAX passenger flights from UK airspace, following Sunday's fatal plane crash in Ethiopia.
"We have, as a precautionary measure, issued instructions to stop any commercial passenger flights from any operator arriving, departing or overflying UK airspace," the UK Civil Aviation Authority (CAA) said in a statement.
Earlier on Tuesday, aviation authorities in Singapore, Australia, Malaysia and Oman temporarily suspended Boeing 737 MAX services after Sunday's MAX 8 flight from Addis Ababa to Nairobi reported technical problems and asked for permission to turn back, before crashing into a field six minutes after takeoff, killing all 157 people on board. Investigations are taking place into the cause of the crash.
This is the second time in less than six months that this model has crashed soon after taking off. A new Lion Air Boeing 737 MAX 8 flight went down over the Java Sea off Indonesia last October, killing 189 people.
"Our thoughts go out to everyone affected by the tragic incident in Ethiopia on Sunday," a CAA spokesperson said in a statement.
"The UK Civil Aviation Authority has been closely monitoring the situation, however, as we do not currently have sufficient information from the flight data recorder we have, as a precautionary measure, issued instructions to stop any commercial passenger flights from any operator arriving, departing or overflying UK airspace.
"The UK Civil Aviation Authority's safety directive will be in place until further notice.
"We remain in close contact with the European Aviation Safety Agency (EASA) and industry regulators globally."
In a statement, Singapore's Civil Aviation Authority announced it would suspend all variants of the Boeing 737 Max aircraft from entering or leaving the city-state, a move affecting SilkAir, China Southern Airlines, Garuda Indonesia, Shandong Airlines and Thai Lion Air.
While no Australian airlines fly the 737 MAX, Australia's Civil Aviation Safety Authority said it would temporarily suspend airlines from flying all Boeing 737 MAX jets to or from Australia.
Oman said on Twitter it is temporarily suspending operations of Boeing 737 MAX aircraft into and out of its airports until further notice.
Malaysia announced that it would suspend the MAX 8 aircraft flying to or from and transiting the country until further notice. No Malaysian carriers currently operate the model.
Airlines including Ethiopian Airlines, Aeromexico, Cayman Airways, South Africa's Comair, South Korea's Eastar Jet and Aerolíneas Argentinas and all Indonesian airlines have said they are temporarily not using the 737 MAX 8.
Those decisions follow the lead of China's aviation administration, who on Monday ordered that all domestic Boeing 737 MAX 8 jets be out of the air by 6 p.m. local time, due to its principle of "zero tolerance for safety hazards."
China has one of the world's largest fleets of Boeing 737 MAX 8, operating 97 of the planes, according to Chinese state-run media.
The fallout has appeared to affect Boeing's bottom line. The aircraft maker's stock dropped 8% Monday, with investors voicing concerns about the 737 and Boeing's future in China , predicted to soon become the world's first trillion-dollar market for jets.
While there is no evidence of a link between the incidents in Ethiopia and Indonesia, similarities between the two have prompted some airlines to take extra safety precautions while both crash investigations are ongoing.
"Given in both air crashes, the aircrafts were newly delivered Boeing 737 MAX 8, and both accidents occurred during the take-off, they share certain similarities," the Chinese aviation administration said in a statement Monday. It added that it would contact Boeing and the U.S. Federal Aviation Administration (FAA) to confirm "flight safety" issues before allowing the planes to fly again.
While some international airlines and governments grounded the 737 MAX 8 planes, US airlines, the FAA and Boeing had not .
CNN aviation expert Richard Quest said of the CAA's decision, "the pressure is now intensifying on the FAA (the US Federal Aviation Administration) when world-respected authorities like the CAA and Australian Civil Aviation Safety Authority have safety concerns about the aircraft."
"It will be very difficult for the FAA to withstand the pressure to actually do something rather than just adopting this wait-and-see approach."
And aviation safety experts and regulators around the world remain divided on whether the Boeing 737 MAX 8 is safe to fly.
"I've never said that it's unsafe to fly a particular model of aircraft, but in this case, I'm going to have to go there," David Soucie, a former FAA safety inspector told CNN, saying that passengers don't have enough information.
Peter Goelz, a former managing director of the National Transportation Safety Board (NTSB) said he believes it's too early for American authorities to ground the jets.
On Monday, Charlie Miller, vice president of communications for Boeing, issued a statement saying the jetliner manufacturer is not planning to issue new guidance "at this point" noting that "the investigation is in its early stages."