BEIJING (AP) -- The death toll in China's latest round of flooding has risen to at least 52, including two schoolchildren aboard a bus carrying more than twice its authorized passenger load that plunged into a pond, authorities said.

At least six other people are missing in floods that have ravaged mountain districts of six provinces and autonomous regions in central and southeastern China. More than a quarter-million people have been moved to temporary shelters, and major damage has been inflicted on buildings and crops.

Apart from the two schoolchildren, 42 others have died due to floods and heavy rains, including 16 in the collapse of a nine-story building in the city of Guiyang following a landslide.

Eight other people were killed in the central province of Hunan when a bus skidded into a guardrail and overturned.

The Guangxi regional government said 21 other kindergarten students were sent to the hospital in the school bus accident on Friday, with three listed in serious condition. The bus was licensed to carry 11 people, but had a total of 26 on board.

The driver, teachers and school administrators have been taken into custody, the government said. Overloaded buses have been involved in accidents killing scores of children in recent years as local schools are closed and consolidated into larger campuses farther away from the children's village homes.

Seasonal rains cause major flooding around China almost every year. The worst in recent history was in 1998, when 4,150 people died, most of them along the Yangtze River.

The massive Three Gorges Dam has largely contained Yangtze flooding, but the problem persists in other parts of the country.