CHONGQING, May 14 (Xinhua) -- A Chinese commercial flight was forced to divert to an alternate airport after a mechanical failure, authorities confirmed Monday.

Flight 3U8633, operated by Sichuan Airlines, was en route from southwest China's Chongqing Municipality to Lhasa, capital of Tibet Autonomous Region. It was forced to divert to Chengdu, capital of Sichuan Province.

According to the Civil Aviation Administration of China (CAAC), part of the cockpit window broke as the Airbus A319 flew over Chengdu. The aircrew enacted emergency code 7700 and landed in Chengdu. All passengers are safe, although the co-pilot sustained injuries to the face and waist, and another crew member was slightly hurt during the emergency landing, according to the CAAC.

Sichuan Airlines confirmed the diversion, and said that an investigation is under way. The plane landed in Chengdu at 7:46 a.m. on Monday.

There were 119 passengers and nine crew members on board, according to the airline, which has arranged another flight to take the passengers to Lhasa.

Video footage shot by passengers showed baggage falling from overhead lockers during the emergency landing and oxygen masks dropping for use.