DHAKA - Bangladesh police said on Thursday they had arrested two members of a banned Islamist group for alleged involvement in the killing of a blogger, the latest attack on critics of religious extremism in the Muslim-majority nation.

Militants have targeted secularist writers in Bangladesh in recent years, while the government has tried to crack down on hardline Islamist groups seeking to make the South Asian nation of 160 million people a sharia-based state.

Blogger Niloy Chatterjee, 40, an advocate of secularism, was killed by attackers armed with machetes in his flat in the capital Dhaka on Friday. It was the fourth such killing of an online critic of religious extremism in less than six months.

Two suspected members of an outlawed Islamist group known as Ansarullah Bangla Team were arrested in Dhaka for links to the killing, senior police official Mahbub Alam said. Chatterjee was also one of hundreds of bloggers driving a movement demanding the death penalty for Islamist leaders accused of atrocities in Bangladesh’s 1971 war of independence.