Sinkhole swarm, Taiyuan, China.

A third sinkhole appeared Friday in the busy downtown area of Taiyuan, capital of north China’s Shanxi Province, after two others caused the partial collapse of a four-storey hospital building Thursday.

No casualties have been reported.

Xinhua reporters saw police telling passers-by to avoid the area.

One police officer complained that it was difficult to stop pedestrians and cyclists passing through the densely populated area.

The new hole measured at about 20 square meters in area and was 6 meters deep. It is 100 meters away from the other two. The smaller of first two is 7 meters long, 4 meters wide and 6 meters deep; and the bigger is 15 meters long, 12 meters wide and 8 meters deep.

Wang Buyun, commander of the emergency headquarters set up to address the issue, said the holes were caused by water leaks from an underground pipeline, which loosened the ground beneath the road.