Watch: Footage shows Chinese airplane nose-diving at speed before crashing

 A China Eastern Airlines Boeing 737-800 with 132 people on board crashed in mountains in southern China on a domestic flight on Monday after a sudden descent from cruising altitude. Media said there were no signs of survivors.

The airline said it deeply mourned the passengers and crew, without specifying how many people had been killed. Boeing said it was ready to assist China Eastern and was in contact with U.S transportation safety regulators over the incident.

Chinese media carried brief highway video footage from a vehicle's dashcam apparently showing a jet diving to the ground behind trees at an angle of about 35 degrees off vertical. Reuters could not immediately verify the footage.

The plane was en route from the southwestern city of Kunming, capital of Yunnan province, to Guangzhou, capital of Guangdong, bordering Hong Kong, when it crashed.

China Eastern said the cause of the crash was under investigation. Such accidents typically involve multiple factors.

The airline said it had provided a hotline for relatives of those on board and sent a working group to the site. There were no foreigners on the flight, Chinese state television reported, citing China Eastern.

Relatives, friends and colleagues of passengers gathered late on Monday in a cordoned off area at the jet's destination, Guangzhou Baiyun International Airport.

One man surnamed Yan said that a colleague had been on the plane, and that he had notified the 29-year-old's mother.

"When she picked up the phone, she choked up," said Yan, adding that he had a "heavy heart" when he heard the news.

China Eastern staff were making arrangements for relatives who wished to travel to the crash site on Tuesday, Yan said. Reuters was not able to independently verify Yan's identity.

The aircraft, with 123 passengers and nine crew on board, lost contact over the city of Wuzhou, China's Civil Aviation Administration of China and the airline said.

The flight left Kunming at 1:11 pm, FlightRadar24 data showed, and had been due to land in Guangzhou at 3:05 pm. 

The plane, which Flightradar24 said was six years old, had been cruising at 29,100 feet at 0620 GMT. Two minutes and 15 seconds later data showed it had descended to 9,075 feet, and 20 seconds after that its last tracked altitude was 3,225 feet.

Media cited a rescue official as saying the plane had disintegrated and caused a fire destroying bamboo trees. The People's Daily quoted a provincial firefighting department official as saying there was no sign of life among the debris.

State media showed a piece of the plane on a scarred, earthen hillside. There was no sign of a fire or personal belongings.

Boeing said last year only 13 percent of fatal commercial accidents globally between 2011 and 2020 occurred during the cruise phase, whereas 28% occurred on final approach and 26 percent on landing.

"Usually the plane is on auto-pilot during cruise stage. So it is very hard to fathom what happened," said Li Xiaojin, a Chinese aviation expert.

Online weather data showed partly cloudy conditions with good visibility in Wuzhou at the time of the crash.

President Xi Jinping called for investigators to determine the cause of the crash as soon as possible, state broadcaster CCTV reported. Russian President Vladimir Putin expressed his condolences to Xi over the incident, TASS news agency reported.

Boeing said in a statement that its thoughts were with the passengers and crew.

"Boeing is in contact with the U.S National Transportation Safety Board and our technical experts are prepared to assist with the investigation led by," the company said.

A person familiar with the matter told Reuters that Boeing has cancelled a meeting of its senior executives scheduled for this week in Miami to focus on assisting the China Eastern investigation.

The disaster comes as Boeing seeks to rebound from several overlapping crises including the coronavirus pandemic and crashes involving its 737 MAX model. Shares in the planemaker were down 3.7 percent at 19:50 GMT.

China Eastern has grounded its fleet of 737-800 planes, state media reported. It has 109 of the aircraft, according to FlightRadar24.

Shares in China Eastern Airlines in Hong Kong closed down 6.5 percent after news of the crash emerged, while its U.S listed shares slumped 17 percent in premarket trading.

'GOOD RECORD'

Aviation data provider OAG said this month that state-owned China Eastern Airlines was the world's sixth-largest carrier by scheduled weekly seat capacity.

The 737-800 has a good safety record and is the predecessor to the 737 MAX model that has been grounded in China for more than three years after fatal crashes in Indonesia and Ethiopia.

​ Investigators will search for the plane's black boxes - the flight data recorder and cockpit voice recorder - to shed light on the crash.

Air crash investigations are typically led by the country of the accident and include participation by the plane's country of origin, so U.S investigators would be expected to join the probe of the U.S made Boeing jet.

The U.S. Federal Aviation Administration said it was ready to assist with China's investigation if asked. The U.S NTSB said it had appointed a senior air safety investigator as an accredited U.S representative to China's probe. 

China's airline safety record has been among the best in the world for a decade, although it is less transparent than in countries like the U.S and Australia where regulators release detailed reports on non-fatal incidents, according to Greg Waldron, Asia managing editor at industry publication Flightglobal.

"There have been concerns that there is some underreporting of safety lapses on the mainland," he said.

According to Aviation Safety Network, China's last fatal jet accident was in 2010, when 44 of 96 people on board were killed when an Embraer E-190 regional jet flown by Henan Airlines crashed on approach to Yichun airport.

In 1994 a China Northwest Airlines Tupolev Tu-154 flying from Xian to Guangzhou crashed, killing all 160 onboard in China's worst-ever air disaster, according to Aviation Safety Network.