Bangladesh's High Court on Sunday confirmed the death penalty for two people tied to a banned Islamist militant group for the killing of an atheist blogger critical of radical Islam.

The court also upheld jail sentences for six others after appeals were filed challenging the verdicts handed down by a trial court in 2015.

Sunday's decision involves the killing of Ahmed Rajib Haider, who was hacked to death in 2013. Haider had campaigned for banning the Jamaat-e-Islami party, which opposed Bangladesh's independence from Pakistan in 1971.

One of the defendants was Mufti Jasimuddin Rahmani, the leader of the Ansarullah Bangla Team, and the rest were university students inspired by his sermons.

During the trial, the students said that Rahmani incited them to kill Haider in sermons in which he said all atheist bloggers should be killed to protect Islam.

The two North South University students who received the death sentences included Faisal bin Nayeem, who the court said hacked Haider with meat cleavers in front of his house in Dhaka, Bangladesh's capital. Another was tried in absentia. The others received prison sentences ranging from three years to life. Rahmani was sentenced to five years.