An oil pipeline has exploded in the Chinese coastal city of Qingdao, killing 35 people, the government says.

The force of the blast on Friday ripped roads apart, turning cars over and sending thick black smoke billowing over the city, pictures showed.

One pedestrian had a leg blown off and another man’s head was crushed under a piece of concrete debris.

The pipeline, run by state-owned oil giant Sinopec, sprang a leak early on Friday and exploded several hours later as workers sought to repair it, the Qingdao municipal government said in its verified account on Sina Weibo, a Chinese equivalent of Twitter.

A total of 35 people were killed, it said, while 166 were injured.

Among the injured, 57 were seriously hurt and eight people were deemed to be in danger of dying, it said.

The cause of the leak was under investigation.

The disaster spurred Chinese President Xi Jinping to urge authorities to do all they can to find survivors, according to state media.

The official Xinhua news agency said he asked for “maximum effort” towards that end and also requested officials to rescue those hurt and improve safety to prevent the occurrence of such incidents.

The explosion site in the eastern province of Shandong is close to the coast and barriers had been set up to stop oil leaking into the sea, it said.