India's Assam state, bordering Muslim-majority Bangladesh, is to issue gun licences to "indigenous" residents, its Hindu nationalist leader has announced, a move raising concerns among the state's Muslims.

Assam Chief Minister Himanta Biswa Sarma has previously warned that the Assamese-speaking population "face the threat of attacks from the Bangladesh side, and even in their own villages".

The northeastern state of around 31 million people is riven by multiple ethnic, linguistic and religious fault-lines, and was troubled by several bloody clashes in past decades.