DHAKA: Bangladesh police said Tuesday they have asked the government to ban an Islamist militant group they suspect of involvement in the murders of atheist bloggers.

Police have already charged members of the Ansarullah Bangla Team with the 2013 murder of blogger Ahmed Rajib Haider, and now suspect the same group was responsible for the deaths of three more bloggers this year.

“Police have asked the home ministry to ban the Ansarullah Bangla Team (ABT),” Dhaka police spokesman Jahangir Sarker told AFP.

Sarker said “primary assessments” had implicated ABT in the recent killings of bloggers including Ananta Bijoy Das, who was hacked to death by machete-wielding attackers on his way to work.

The 33-year-old was the third secular blogger to be killed in the Muslim-majority nation since February when Bangladeshi-born US citizen Avijit Roy, a writer and moderator of a blog site, was hacked to death in the capital Dhaka.

Read more: Third secular blogger hacked to death in Bangladesh

The deaths have sparked international condemnation and protests in the capital Dhaka.

Fellow writers said Das was on a hit-list drawn up by militants who were behind Roy's killing.

No one has yet been charged over Das's death, but his brother has filed a criminal case saying he was murdered by an “extremist fanatic group”.

Hours after the murder, a group called Ansar Al-Islam said on Twitter that Al Qaeda in the Indian Subcontinent (AQIS) was responsible for Das's murder and warned of more to come.

Bangladesh is an officially secular country but more than 90 percent of its 160 million population are Muslim.

The country has seen a rise in attacks by religious extremists in recent years.

AQIS has already claimed responsibility for the February 26 attack in Dhaka that killed Roy and also badly injured his wife. An Islamist has been arrested over his murder but not formally charged.

Read more: Protest over secular blogger’s murder in BD

Sarker said police were investigating whether ABT had links with Al Qaeda, adding that the group was more sophisticated than some of its better known counterparts in Bangladesh.

“They do not operate like the others. They are highly strategic and they are highly trained,” he said. The home ministry did not comment on whether it would ban the group.