Police in Bangladesh have arrested a home-grown Islamist militant over the killing of two gay rights campaigners amid a surge in violent attacks against liberal activists and other minorities in the south Asian nation.

Police in Bangladesh say unidentified assailants have stabbed two men to death, including a gay rights activist who also worked for the US Agency for International Development.

Two men, including a gay rights activist who worked for the US Agency for International Development, have been stabbed to death in Bangladesh.