Bangladesh wildlife officials try to rescue an elephant stuck in the flood. (AFP)
Bangladesh and India are mounting a major rescue effort for a wild elephant struggling to survive after it was separated from its herd by floods and then washed across the border.
On Thursday, three Indian forest officials will travel to a flood-hit area in northern Bangladesh to investigate how they can help the stranded animal, which was separated from its herd in Assam more than a month ago.
A vet dispatched to the scene by Bangladesh authorities said the elephant, a female that weighs an estimated four tonnes, was "weak and tired" after its solo odyssey across the Brahmaputra river that separates the two countries.
"For the last month it has been separated from its herd and stranded mostly in flood water," Sayed Hossain told news agency AFP.
"It crossed the mighty Brahmaputra and has been living mostly on paddy (rice) crop, sugar canes and a limited amount of banana plants."
Forestry official Shahab Uddin said thousands of villagers in boats have been following the elephant, which has so far crossed around 100 kilometres (60 miles) of flooded terrain in northern Bangladesh.
Bangladeshi authorities have dispatched a team of forest rangers, police inspectors and vets to track the wild animal, but the floods were hampering rescue efforts.
"Our effort to rescue the animal has been hampered by ongoing floods as there is no way we can tranquillise it in water as it might be floated downstream. The elephant must be driven to a higher ground in a bid to rescue it," Uddin said.