Armed policemen patrol near the exit of the South Railway Station, where three people were killed and 79 wounded in Wednesday's bomb and knife attack, in Urumqi, Xinjiang Uighur Autonomous region, May 2, 2014. REUTERS/Petar Kujundzic
Armed policemen patrol near the exit of the South Railway Station, where three people were killed and 79 wounded in Wednesday's bomb and knife attack, in Urumqi, Xinjiang Uighur Autonomous region, May 2, 2014. REUTERS/Petar Kujundzic
Armed policemen patrol near the exit of the South Railway Station, where three people were killed and 79 wounded in Wednesday's bomb and knife attack, in Urumqi, Xinjiang Uighur Autonomous region, May 2, 2014. REUTERS/Petar Kujundzic

At least 31 people died in China after two sports utility vehicles crashed into the shoppers at a market in Urumqi, capital of restive Xinjiang region, and then threw explosives. State-run Xinhua news agency said more than 90 people were injured in the explosion.

China's Ministry of Public Security described it as "violent terrorist incident."

It was the fourth deadly terrorist attack in a month. It followed a bomb and knife attack at an Urumqi train station on April 30, which killed three people, and a train station assault in the southern city of Kunming in March where 33 people died.

In a statement, the Xinjiang regional government said the attack occurred at 7:50 a.m.

"I heard four or five explosions. I was very scared. I saw three or four people lying on the ground," The Australian quoted Fang Shaoying, the owner of a small supermarket located near the scene of the blast. Pictures taken by eyewitnesses posted on Weibo, China's Twitter, appeared to show the bombing occurred at one end of a busy market street lined with stalls selling vegetables.

"Witnesses said two cross-country vehicles driving from north to south ploughed into people in the market. Explosives were thrown out of the vehicles," the Xinhua report said.

Twitter photos showed at least three people lying in a street with a large fire in the distance giving off huge plumes of smoke. Road blocks were being manned by police in helmets and body armor as police cars, ambulances and fire trucks arrived in the scene. Other people were in shock while seated in the roadway.