DHAKA: A Bangladesh publisher who worked with atheist writers was hacked to death in the capital Dhaka on Saturday, his father and police told AFP, just hours after two secular bloggers and another publisher were attacked in a separate incident.

Faisal Arefin Dipan, 43, was killed in his third-floor office in central Dhaka, his father Abul Kashem Fazlul Haq, who is a noted Bangladesh intellectual and writer, told AFP.

“I saw him lying upside down and in a massive pool of blood. They slaughtered his neck. He is dead,” he said.

The incident came just hours after unidentified assailants attacked two secular writers and another publisher, leaving one of them in a critical condition, according to police.

“He published the books of Avijit Roy. They also attacked other publishers of Roy but only my son died,” Haq said.

Read: Bangladesh arrests militant chief over blogger murders

Atheist wrier and blogger Roy was hacked to death near a book fair in the capital Dhaka in February this year -- the first in a series of attacks this year that have targeted atheist and secular bloggers in Bangladesh, leaving five dead.

Police inspector Mozammel Haq also confirmed Dipan's death.

Police said Dipan's father alerted officers after he could not reach him by phone.

“Officers entered his office and found him in a pool of blood. He was hacked in the neck and head,” assistant commissioner of police Shiblee Noman told AFP.

Dipan owns Jagritee Publishers based at Aziz Supermarket, a hub for alternative and small publishers in Dhaka.

Earlier in September, Bangladesh's elite security force arrested the head of a banned hardline Islamist group over the murders of two atheist bloggers that sparked an international outcry.

Prime Minister Sheikh Hasina's secular government has vowed to hunt down the killers, following international outrage and accusations it failed to stop the attacks, wary of a political backlash from Islamists.

Police have stepped up security for those being threatened and thought to be on the hit-list drawn up by a hardline Islamist group.

Islamists have long clashed with young secular activists whom they consider infidels for criticising Islam on social media, some of them under pen names.

But the gruesome killings have shaken many in Bangladesh which prides itself on being a mainly moderate Muslim country.

The impoverished and officially secular nation of 160 million has largely rejected Islamic extremism since gaining independence.