DHAKA (AFP) - About 30 people were feared drowned after an overcrowded bus plunged into a deep river in southern Bangladesh on Wednesday, police said.

The accident occurred as the bus was about to be driven onto a river ferry in the district of Barisal, local police chief Nurul Islam told AFP.

"We've found eight people who managed to swim to the bank from the submerged bus. They said the 32-seater bus was overcrowded and carrying more than 40 people. About 30 people are still unaccounted for," police chief Islam said.

Divers were seeking to recover the victims from the river, he added.

Road accidents are commonplace in Bangladesh and kill thousands of people each year with badly maintained vehicles and rash driving blamed for many deaths.

In February, a bus carrying pilgrims to Bangladesh's beach resort town of Cox's Bazaar plunged into a dry river bed, killing at least 17 people.