BEIJING, China (AFP)- China Eastern Airlines resumed flying Boeing 737-800 aircraft on Sunday, flight tracking data showed, just weeks after it grounded 223 planes over a crash that killed 132 people.

READ: Chinese airliner crashes with 132 aboard in country’s south

Flight MU5843, operating the 800 variant of the 737, departed the southwestern city of Kunming at 9:58 am local time (0158 GMT) and landed in Chengdu at 11:03 am, according to Flightradar.com.

The three-year-old jet later returned to Kunming from Chengdu, with further flights scheduled for Tuesday.

Flight MU5735 — a 737-800 — was en route from Kunming to Guangzhou on March 21 when it nosedived into a mountainside, disintegrating on impact.

The jet dropped 20,000 feet (6,096 metres) in just over a minute. The velocity of the impact left twisted metal and passengers’ belongings scattered across a vast swathe of forest.

The cause of the disaster, China’s deadliest plane crash in more than 30 years, is not yet known.

The accident caused China Eastern to ground all of its 737-800s for safety checks as aviation authorities vowed an extensive two-week inspection of China’s vast passenger fleet.

Authorities have retrieved both black boxes from the downed jet, which are currently being analysed at an American lab with the help of investigators from the United States government.

A preliminary investigation report would be completed within 30 days of the crash, the government previously said.

China Eastern’s resumption of 737-800 flights on Sunday came as Boeing awaits approval to resume operation of the 737’s MAX variant in China, the last major market yet to give the green light.

The 737 MAX was temporarily grounded worldwide following two crashes in Indonesia and Ethiopia that killed a combined 346 people in 2018 and 2019.