Some 20 people were injured in an explosion caused by a gas leak at a construction site for an underground commercial street in Shenyang, Liaoning province, on Monday, according to the city's information office.

Five people suffered head and facial injuries, though none are life-threatening. The reason for the accident is still under investigation, according to the information office.

An Yang, a witness, said heavy white smoke followed the bursts. The huge impact shattered glass in several buses, taxies and even surrounding buildings. Four manhole covers were blown off. "It's awful. Like a disaster movie."