The leader of Al Qaeda’s branch in the Indian subcontinent has published a video claiming responsibility for the death of Avijit Roy, an atheist Bangladeshi-American blogger who was killed by a group of men with machetes on Feb. 26 as he was leaving a book fair in Dhaka, Bangladesh.

In a nine-minute video posted on jihadist forums on Saturday, the leader of the branch, Asim Umar, said followers of his group were responsible for the killing of several people he called blasphemers: Mohammad Shakil Auj, an Islamic scholar fatally shot in Karachi, Pakistan, in 2014; Aniqa Naz, a Pakistani blogger; Rajib Haider, a blogger killed in a machete attack in Dhaka, the Bangladeshi capital, in 2013; and Mr. Roy.

“They have taught a lesson to blasphemers in France, Denmark, Pakistan and now in Bangladesh,” Mr. Umar said in the video, which was translated and published by the SITE Intelligence Group, which monitors extremist activity online.

He went on to urge his followers to carry out more attacks, saying, “Where are those who would kill these blasphemers, wherever they may be found, even if it has to be done using a dagger or a knife, and by doing so record their names on the Day of Judgment among the devotees of the prophet?”