Villagers armed with sticks and boat oars beat a Bengal tiger to death on Tuesday after it attacked a fisherman in southwestern Bangladesh, an official said.

The critically endangered animal from the UNESCO-listed Sundarbans, the world's largest mangrove forest, strayed into Naodag village in the morning and bit the fisherman on his hand before trying to drag him away.

"The other villagers rushed to rescue the man and beat it to death," Amir Hossain Chowdhury, the government's chief conservation officer for the Sundarbans forest, told AFP.

Bangladesh has formed patrols to try to stop villagers attacking the animals, but Chowdhury said the tiger was already dead by time they could reach Naodag.

There are around 440 Bengal tigers in the Bangladeshi section of the Sundarbans, according to a 2004 government census. Experts say the number is much less, with many falling victim to attacks by villagers after straying onto farms.

There have been 14 registered cases of tigers being killed in similar circumstances since 2000.

The Sundarbans lie on the delta of the great Himalayan rivers, the Ganges and the Brahmaputra. Covering 10,000 square kilometres (3,860 square miles), it is the world's largest mangrove forest and straddles India and Bangladesh.