An explosion in a restaurant in a tourist city in northwestern China on Monday killed at least nine people and injured another 34, state media said.

The explosion happened at the start of the morning rush hour in a fast-food restaurant in Xi'an, the capital of Shaanxi province and home to China's ancient terra cotta warriors, according to a report on the website of the Xi'an Daily, which is run by the Communist Party's local propaganda department.

The official Xinhua News Agency said an initial investigation blamed a liquified petroleum gas leak. The explosion knocked out windows as far as a mile (about two kilometers) away.

Photos online showed the front of a building had been blown into a street, where there were bodies covered in blue plastic.

Many of the victims, including children, were walking by the front of the restaurant or waiting for a bus, the website said.

Xinhua quoted a doctor as saying many people had wounds to the face and head and an unnamed witness as saying that many people rushed out on to the street with bleeding heads and hands.

The news agency also quoted 11-year-old Gong Yejian, whom it said was passing by the building when the explosion happened.

"The blast knocked me down with glass fragments hitting my body from head to toe," Gong said, in hospital with face and head wounds. "The tree near me fell down as well."