Police officers stand guard near a blast scene, which has been cordoned off, in downtown Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region, May 22, 2014. An unknown number of people were killed and injured after explosions occurred Thursday morning at an open market in Urumqi. Witnesses said two cross-country vehicles driving from north to south ploughed into people in the market at 7:50 a.m. Explosives were thrown out of the vehicles. One of the vehicles exploded in the market. All injured people have been sent to hospital while investigations are underway. (Xinhua/Cao Zhiheng)

 An unknown number of people were killed and injured after explosions occurred Thursday morning at an open market in Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region.

All the injured were rushed to several hospitals, police said.

Witnesses said two cross-country vehicles driving from north to south ploughed into people in the market at 7:50 a.m. Explosives were thrown out of the vehicles.

One of the vehicles exploded in the market.

A business runner in the market told Xinhua he heard a dozen of big bangs.

The open air morning market is located near the Renmin Park in downtown Urumqi. Ambulance and police cars are parking at the entrance of Park North Street leading to the market.

Flames and heavy smoke were seen. The scene has been cordoned off.