Blast in northern China kills at least seven

An explosion tore through a building in northern China Monday killing at least seven people, injuring dozens more and shattering windows up to three kilometres away, officials and state media said.

The cause of the blast, which happened early Monday in the city of Xian, known for its Terracotta Warriors, was not immediately clear.

However, the official Xinhua news agency quoted a witness as saying it appeared to be a gas explosion at a first-floor restaurant.

Photographs purportedly of the scene posted online showed destroyed cars, shattered glass and other debris outside a modern high-rise building.

"Thirteen people were sent to our hospital, and three died -- two male adults and a three-year-old girl. One is in critical condition," a doctor surnamed Han at the Shaanxi Renmin Hospital told AFP.

Another 19 people injured in the blast were sent to the Xian Gaoxin Hospital and four of those had died, a nurse surnamed Wu told AFP. The condition of the other 15 people was not clear.

Doctors said victims had suffered head and facial injuries, Xinhua said.

Xinhua said the building was an office tower in Gaoxin district of Xian.

Photos posted online showed a number of fire engines and ambulances parked on the street outside the building.

The blast appeared to have shattered the windows of the first two floors of the tower, with glass, mangled parts of the building and other debris littering the ground.

The force of the explosion blew away a sign board at a nearby bus stop and broken window panes were seen two to three kilometers from the site, Xinhua said.

An official at the local public security bureau told AFP that emergency workers were still attending to casualties and they did not yet know the total number of dead and injured.

China has a notoriously poor record of workplace accidents, blamed on widespread disregard for basic safety measures as companies chase profits.

A coal mining accident in the southwest province of Yunnan last week killed at least 34 workers, with hopes fading of finding alive nine others still trapped underground, officials said Monday.

Earlier this month, two vehicles carrying explosives detonated in the southwest province of Guizhou killing at least seven people, seriously injuring 20 and causing several nearby buildings to collapse.

The two vehicles were transporting 70 tonnes of explosives, state media reported.