BEIJING (AP) — Twenty-two people are trapped in a coal mine in China after a rock burst destroyed part of a mining tunnel, officials said Sunday.

The spontaneous fracturing of rock — a kind of earthquake induced by excavation — took place around 11 p.m. Saturday in eastern Shandong province, the official Xinhua News Agency reported.

More than 300 people were working inside the mine at the time. Most have been successfully lifted to safety while 22 remain stuck underground.

The incident "has nothing to do with workers' operations," an official with the Shandong Coal Mine Safety Supervision Bureau told the Associated Press by phone. The official, surnamed Tian, said nearly 140 rescuers were dispatched.

About 100 meters (328 feet) of a roadway within the mine was also damaged, said Xinhua.