A truck drives into a restaurant in Delong county, northwestern Ningxia Hui autonomous region, Dec 14, 2011. [Photo/Xinhua]

YINCHUAN - Seven people were killed on Wednesday afternoon after a truck drove into a restaurant in Delong county, northwestern Ningxia Hui autonomous region, said local police.

The accident happened at about 4:30 pm when a truck crushed into a two-floor restaurant along an expressway in Delong.

At least seven people were killed on the spot. Some are still trapped inside the seriously damaged restaurant. Firefighters are racing to rescue the trapped people.

According to initial investigation, brake failure might have caused the accident.

The exact number of the injured is still unknown.