China Eastern Airlines has restarted using Boeing 737-800 jetliners for commercial flights less than a month after a crash that killed 132 people on board and grounded over 200 of its aircraft, data from a tracking website showed on Sunday.

China Eastern flight MU5843, operated by a three-year-old Boeing 737-800 aircraft, took off from the southwestern city of Kunming at 09:58 a.m. local time (0158 GMT) on Sunday and landed at Chengdu, also in southwestern China, at 11:03 a.m. local time, data from Flightradar24 showed.

That aircraft, which completed a test flight on Saturday, departed Chengdu at 13:02 p.m. for Kunming, according to Flightradar24.

Another Boeing 737-800 jet conducted a test flight on Sunday morning in Shanghai, where China Eastern is based, Flightradar24 data showed.

China Eastern was not immediately available for comment.

On March 21, Flight MU5735, which was en route from Kunming to Guangzhou, crashed in the mountains of Guangxi and killed 123 passengers and nine crew members in mainland China's deadliest aviation disaster in 28 years.

China has retrieved both of the black boxes and has said it would submit a preliminary report to the U.N. aviation agency ICAO within 30 days of the event.

(Reporting by Stella Qiu and Ryan Woo; Editing by Muralikumar Anantharaman)