At least 31 people were killed and 90 others injured in a series of explosions in an open-air market in Urumqi, capital of China’s restive Xinjiang province which is home to mostly Muslim Uighurs, the bloodiest “terror” attack in recent years blamed on radical separatists.

Witnesses said two cross-country vehicles ploughed into people in the busy market at 7:50 a.m and explosives were thrown out of the cars by persons sitting next to the drivers, state-run news agency reported.

One of the vehicles exploded in the market causing heavy casualties. At least 31 people were killed and 90 others injured in over dozen explosions, news agency said.

Injured were rushed to different hospitals, police said.

As the news broke out, President Xi Jinping vowed to severely punish terrorists and spare no efforts in maintaining stability, Ministry of Public Security said, describing the incident as a “serious violent terrorist incident”.

Pictures released on Weibo, akin to Twitter, showed widespread damage with several bodies lying in the street besides thick smoke raising above Urumqi’s skyline.

A businessman in the market told that 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 parked at the entrance of the street leading to the market helped evacuate the injured.

Flames and heavy smoke were seen nearby while the area had been cordoned off after the blast.

Xinjiang, bordering Pakistan-occupied Kashmir and Afghanistan, has been plagued by violence for years.

Chinese officials suspect that the explosions were caused by the East Turkistan Islamic Movement, an al-Qaeda affiliate, which has been blamed for a spate of recent violence including the dreaded knife attacks in and out of Xinjiang province.

Xinjiang region has witnessed riots between native Muslim Uygurs and Han settlers from outside the province.

Uygurs, a Turkic speaking community, resent the settlements as they believe the large scale migration is marginalising them in their own homeland.