Australia and Singapore on Tuesday banned Boeing 737 MAX planes from their airspace and airlines around the world grounded the jets following a second deadly accident in just five months.

A SilkAir Boeing 737 MAX aircraft (background C) is parked on the tarmac of Changi International Airport in Singapore on March 12, 2019. (Photo: AFP)

On Sunday a new Ethiopian Airlines 737 MAX 8 went down minutes into a flight to Nairobi, killing all 157 people on board. It came after a Lion Air jet of the same model crashed in Indonesia in October, killing 189.

Investigators have recovered the black box flight recorders from the Ethiopian Airlines plane, which went down near Addis Ababa carrying passengers and crew from 35 countries -- including some two dozen UN staff.

US regulators have ordered Boeing to make urgent improvements to the model and insisted they would take action if safety issues are detected. 

But it was not enough to reassure aviation authorities in other countries, with Singapore and Australia temporarily banning all 737 MAX planes from their airspace. 

China, a hugely important market for Boeing, had already ordered domestic airlines to suspend operations of the plane Monday, as did Indonesia.

Aviation regulators in Singapore, a global air travel hub and popular transit point for long-haul travellers, said they would work with the country's main airport and "the affected airlines to minimise any impact to travelling passengers". 

One Singapore airline, SilkAir, uses 737 MAX aircraft while a handful of foreign airlines operate the planes in the city-state.

Australia's regulator said it regretted "any inconvenience to passengers but believes it is important to always put safety first". Only one Fijian airline is affected by the Australian ban.

South Korea meanwhile ordered the only airline in the country that operates the jets to suspend operations of its two MAX 8s. Argentina's flag carrier also grounded five MAX 8 aircraft on Tuesday, as did airlines in countries including South Africa, Brazil and Mexico.

But several airlines have said they are not cancelling MAX 8 flights, while US carriers appear to maintain confidence in the manufacturer.

"The Boeing 737 MAX is a highly sophisticated aircraft," said India's SpiceJet, which has 13 of the model 8 variant in its 75-strong fleet.

"It has flown hundreds of thousands of hours globally and some of the world's largest airlines are flying this aircraft," it said in a statement.