A Chinese domestic flight carrying 132 people crashed Monday afternoon in the Guangxi Zhuang Autonomous Region in the country's south. A rescue operation is underway. No details, including the number of casualties, have been released.

Chinese aviation authorities say China Eastern Airlines Flight 5735 took off from Kunming in the southern Chinese province of Yunnan for Guangzhou in Guangdong Province.

The authorities say they lost contact with the Boeing 737 at around 2:15 p.m. while it was flying over Wuzhou City in the autonomous region. They later confirmed that it crashed in a mountainous area.

The authorities say 123 passengers and nine crewmembers were on board.

Video footage posted on the social media account of the Chinese Communist Party newspaper, the People's Daily, shows white smoke billowing from the mountains and what appears to be a metal part from the plane on a mountain path.

Flightradar24, a website of a private organization, shows flight route information such as locations and altitudes based on signals from flying planes.

According to the site, Flight 5735 left Kunming shortly after 1:10 p.m. on Monday and headed east.

About an hour after takeoff, its altitude suddenly plunged from about 9,000 meters, and eventually dropped under 1,000 meters. The plane's trail disappeared over Wuzhou City.