Beijing ? The bank of a rain-swollen river collapsed early Thursday in southern China, flooding 11 villages filled with sleeping people and causing an unknown number of deaths and injuries, state media reported.

The river bank collapse in Fujian province came amid what the government calls the worst summer flooding in some areas in three decades. At least 55 people have been killed in Fujian and two other provinces since late May from heavy rains that have caused floods and landslides and washed away part of a rail line between Beijing and Hong Kong. Twelve people are missing.

Fujian’s Changting county saw more than 3 1/2 inches of rain in two hours, sending the Bashili River over its banks and sweeping through the 11 villages around 3 a.m., the government’s Xinhua News Agency reported, citing provincial flood control officials.

Some 3,500 families lived in the villages, parts of which were covered by 6 feet of water, the report said. “Most of the people were asleep, so there’s no way to calculate the number of casualties and the loss of property,” Xinhua said.

However, a man who answered the phone at the Changting county Public Security Bureau said his colleagues were at the site and there were no reports of deaths so far. He would only give his surname, Li.

Rescue crews, including paramilitary police and fire brigades, helped evacuate more than 16,000 people from the area and were reinforcing the river bank with sand bags, Xinhua said.

Across southern China, at least 378,000 people have been evacuated from Fujian, Guangdong and Guizhou provinces due to floods, the Ministry of Civil Affairs said.