DHAKA (Reuters) - The High Court of Bangladesh on Sunday upheld the death sentences of two members of a banned Islamist group accused of killing a blogger, a court official said.

The two were sentenced to death in 2015 for killing Ahmed Rajib Haider, a youth group activist campaigning for a trial of war criminals, including those involved in Bangladesh’s independence war with Pakistan in 1971.

Rajib was hacked to death in Dhaka in 2013.

The two convicts, Redwanul Azad Rana and Faisal Bin Nayem, are members of the Islamist group Ansar al Islam, linked to al-Qaeda. In 2015, Dhaka police announced a reward of 500,000 taka ($6,410) for Rana, believed to be the most senior leader of the group. He has gone into hiding.

Rana is also accused of hacking to death another blogger, Bangladesh-born U.S. citizen Avijit Roy, in the same year.

Bangladesh has been battling a rise in Islamist-linked violence in the past four years. Since July, several militants have been arrested or killed in police operations for involvement in last year’s attack on a Dhaka cafe in which 22 people, mostly foreigners, were killed.

Since 2013 Islamist militants killed or seriously injured 48 people in Bangladesh, including at least six online critics of religious militancy who were hacked to death.

Islamic State and al Qaeda have made competing claims over the killings of foreigners, liberals and members of religious minorities in Bangladesh, a mostly Muslim country of 160 million people.

The government has consistently ruled out the presence of foreign groups, blaming domestic militants instead.