Protesters rallied in the Bangladesh capital on Sunday over the latest attacks against secular writers and publishers, accusing the government of failing to halt rising deadly violence blamed on hard line Islamists.

Teachers, writers, students and other protesters converged on Dhaka University to vent their anger, one day after a gang of men armed with machetes and cleavers hacked to death a publisher of secular books.

Two secular bloggers and another publisher were also badly injured in a similar and separate attack in Dhaka on Saturday, leaving them in pools of blood in their office.

"First they targeted the writers, and now the publishers, and soon they'll target all of us," Samina Lutfa, a teacher at the university, told the rally of around 200 protesters.

"Don't stay at home, come out on the street and protest these killings," she said at the campus, Bangladesh's secular bastion, as protesters called for similar rallies elsewhere in the country.

Fears of Islamist violence have been rising in Muslim-majority Bangladesh after four atheist bloggers were murdered this year, allegedly by Islamist hard-liners.

Al-Qaida in the Indian Subcontinent claimed responsibility for Saturday's attacks, along with the four earlier ones, branding the victims "blasphemers" and warning any writers who criticize Islam of being next in line.

Bloggers say about a dozen secular writers have fled the country in fear following this year's killings, while some have faced threats themselves from Islamists.