Vehicles plowed through an open market and set off explosions in Urumqi, capital of China's Xinjiang Uygur autonomous region, on May 22, killing at least 31 people and injuring more than 90 others, NBC News reported.

The Xinjiang government labeled the morning attack "a serious violent terrorist incident of a particularly vile nature," the report quoted AP as saying.

The US Embassy said in a posting on Sina Weibo, the Chinese equivalent of Twitter, that it offered condolences to victims of the "violent attack."

Britain's Foreign Secretary, William Hague, said he was "saddened to hear about the terrorist attack."