Monsoon storms have flooded parts of eastern India and Bangladesh, washing some 33 fishing boats out to sea in the Bay of Bengal.

Officials say at least 500 fishermen are unaccounted for after a tropical depression swept through India's West Bengal state late Thursday.

At least seven people were reportedly killed in the state, including in the capital, Kolkata, where heavy rains flooded roadways and uprooted trees. In some areas of West Bengal, the rains triggered landslides that flattened homes.

The tropical depression also hit parts of neighboring Bangladesh, where fishermen were put on high alert at Cox's Bazar and other ports.

South Asia's monsoon season runs from June to September and is vital to millions of farmers who rely on the rains to irrigate their land.