Unprecedented heavy rain has left six people dead in southwest China's Chongqing Municipality, local authorities said Thursday.

The casualties were reported after rainstorms pelted Dianjiang County from Wednesday night to Thursday morning, according to county officials, with the maximum daily precipitation measured at 254.6 millimeters, a record high since the county had meteorological records.

Four people died from geological disasters triggered by heavy rainfall and two others drowned. 

Vehement downpours have hit the municipality since Wednesday evening, raising water above alert levels in 15 rivers.

(With input from Xinhua)