India has stepped up security on its border with Bangladesh after an official in the country’s new government threatened to annex part of the north-east.

Mahfuz Alam, a senior adviser to new interim leader Muhammad Yunus, accused the Indian government in a Facebook post on Dec 16 of “ghettoising”’ and “colonising” the population in West Bengal, Tripura and Assam.

Bengali-speaking Muslims are the largest minority in all three states.

For Bangladesh to succeed as a country following the overthrow last year of pro-India prime minister Sheikh Hasina, it must grow geographically, Mr Alam wrote.

“A small, limited, landlocked” nation, he argued, would be doomed to fail, adding that the culture of north-east India has more in common with Muslim-dominated Dhaka than Hindu-majority Delhi.