Updated

BEIJING (AP) — The water supply was safe in a northeastern China city after more than 3,000 containers of toxic chemicals were washed into a river by the worst floods in a decade in the country, an official said Thursday.

Some of the water supply in Jilin city in Jilin province was shut off for maintenance purposes Wednesday, the official Xinhua News agency reported, without saying whether the move was because of the spill.

Workers began cleaning up the thousands of barrels — which contained a flammable chemical used to make rubber and adhesive — that had tumbled into the Songhua River near Jilin after a flood swept through a local factory, Xinhua said.

The Jilin environmental protection agency and water bureau fanned out around the city testing water sources and checking for possible leaks in the barrels, said an official with the Jilin Water Bureau. She refused to give her name as is common with Chinese officials.

"Some residents are worried, but we have yet to find any leaks in the barrels of chemicals, so they should not be worried about their water quality," the official said.

The Songhua has had environmental problems before. In 2005 carcinogenic chemicals, including benzene, spilled into the river, forcing the northeastern city of Harbin to sever water supplies to 3.8 million people for five days.

Floods this year have killed at least 928 people, left 477 missing and caused tens of billions of dollars in damage, the State Flood Control and Drought Prevention office reported. More heavy rains were expected for the southeast, southwest and northeast parts of the country through Friday.

That included about 30,000 residents trapped and left without power in their homes in Jilin after torrential rains drenched the town of Kouqian, Xinhua reported.

Flooding has hit areas all over China. Thousands of workers sandbagged riverbanks and checked reservoirs in preparation for potential floods expected to flow from the swollen Yangtze and Han rivers, said an official with the Yangtze Water Resources Commission. He gave only his surname, Zhang, as is common with Chinese officials.

Although China experiences heavy rains every summer, flooding this year is the worst in more than a decade because the flood-prone Yangtze River Basin has seen 15 percent more rain than in an average year, Duan Yihong, director of the National Meteorological Center, said in a transcript of an interview posted on the Xinhua website.

"Rains should begin to slow down in August, but it is hard to predict now what exactly will happen," said Duan. "We have to be vigilant and closely monitor the weather ... do a better job of forecasting."

Around China, a total of 875,000 homes have been destroyed, 9.61 million people evacuated, and 22 million acres (8.76 million hectares) of crops ruined in this year's flooding, according to the state flood control office.

China's worst flooding in recent years occurred in 1998, when 4,150 people were killed, most along the Yangtze.