At least 23 people have been killed and 30 are still missing as of Sunday evening after the worst rainstorm of the year lashed southwest China's Sichuan Province late Friday, the provincial civil affairs department said.

Villagers are trapped on the second floor of a building in Quxian County.

More than 586,000 people were forced to evacuate their homes as torrential rains pounded 62 counties and cities in the province and triggered mountain torrents, landslides and house collapses, cutting off roads, electricity and communications in some regions.

Half of the worst-hit Quxian County remains flooded, with water levels of up to 10 meters deep. The county is cut off from the outside world, with roads and railways flooded by waters, according to a spokesman with the department.

"We can only see the roofs of most riverside houses in Qujiang Town and Jubei Town," said Deng Yuhua, secretary of the county's Party committee.

Further, rains are still pelting eastern parts of the province, which will probably aggravate the situation, said the spokesman.

Flooding is forecasted to peak in Guang'an City, at the lower reaches of Qujiang River, on Monday.

The provincial government has dispatched work teams and allocated emergency funds of 5 million yuan (about 730,000 U.S. dollars) to support flood relief operations.

Parts of China experience heavy rains every summer, but this year's rains have been particularly devastating.

Since the beginning of July, torrential rains and severe flooding has left 146 people dead and 40 missing and forced the evacuation of more than 1.3 million people as of 4 p.m. Friday in 10 provinces, mostly along the Yangtze River, according to the Ministry of Civil Affairs.