China is stepping up monitoring of water levels in its rivers and reservoirs, the government said, after rainstorms hit the south earlier this month and left dozens of people dead or missing.

Parts of southern China are prone to rainstorms during spring and summer.

Pictures from Guizhou province at the weekend showed people trying to push cars along roads wheel-deep in muddy brown water, and people wading through water halfway up their thighs.

Torrential rains this month, sometimes accompanied by hail, had killed 55 people and left another 14 missing by May 17, according to the latest available official national toll from the ministry of civil affairs.

New storms struck nine provinces and municipalities across the country over the weekend, with the levels of some rivers exceeding danger lines, said the ministry of water resources.

Authorities have ordered local governments to increase reservoir and dyke patrols to "stamp out risks", it said in a statement on Sunday.

"We can never slacken over anti-flood work," it said, adding the rains were moving to the east.

Last year 673 people were killed and 159 went missing in floods across the country.