The crash of an airliner on Monday ended China's civil aviation safety record of more than 4,000 days.
A China Eastern Airlines aircraft carrying 132 people crashed in South China's Guangxi Zhuang autonomous region on Monday, according to the Civil Aviation Administration of China.
Search and rescue teams have been sent to the crash site.
China's safety record of civil aviation has remained among the best in the world over the past decade.
"As of the end of February, China's civil aviation record for safety stood for 138 months, handling 5.11 billion passenger trips safely," Wu Shijie, deputy director of the administration's safety office, told a monthly routine news conference last week.
According to data from flightradar24, a global flight tracking service, the plane reached a cruise altitude of nearly 9,000 meters shortly after departing from Kunming at 1:11 pm. It plunged nearly 8,000 meters in 3 minutes at 2:19 pm and crashed on the mountain.
The aircraft was a nearly 7-year-old Boeing 737-800 passenger jet, one of the company's most widely used aircraft.
China Eastern Airlines suspended all the Boeing 737-800 jets after the crash. The airline has changed its website color to black and white in mourning for the victims.
China Eastern Airlines Hong Kong shares plunged on Monday afternoon, dropping more than 8 percent to close down 6.46 percent. The company's US shares and Boeing shares also fell sharply.
According to the airline, as of February, it operates 752 jets of various types. Boeing China said they were aware of the crash news and were gathering more information, according to China Central Television.
The accident has triggered discussion about the safety of the Boeing 737 series, which includes various types of jets, such as the 737-600, 737-700 and 737 Max.
The Boeing 737 Max was grounded around the world after two fatal crashes that killed 346 people－an Ethiopian Airlines jet crashed six minutes into a flight from Addis Ababa in March 2019, less than five months after a Boeing 737 Max flown by Indonesia's Lion Air plunged into the Java Sea.
On March 11, 2019, China grounded its fleet of 97 Boeing 737 Max jets, the first country to do so.
An airworthiness directive on the Boeing 737 Max was issued by the Civil Aviation Administration of China in December after soliciting opinions from the industry. The jet has not yet resumed operations in China.
The civil aviation industry has also been hit hard globally by the COVID-19 pandemic, including in China, leading to salary reductions and staff layoffs.
According to a report released by the International Air Transport Association in October, the global civil aviation sector suffered an estimated net loss of $51.8 billion last year.
China's last fatal jet crash was on Aug 24, 2010. An Embraer E-190 regional jet of Henan Airlines crashed in Yichun, northeastern China's Heilongjiang province. Forty-four people were killed and 52 were injured.