SITE tweeted the claim citing IS’ Amaq News Agency hours after the English department professor was hacked to death early in the morning on Saturday.
SITE says the terrorist group killed Karim for “calling to atheism” in Bangladesh.
“#ISIS' 'Amaq Agency reported the group's responsibility for killing Rajshahi Univ. prof Rezaul Karim for "calling to atheism" in #Bangladesh,” reads the SITE tweet.
Siddiquee, who used to write and was involved with several cultural organisations, was murdered in a similar manner followed in the recent killings of bloggers and online activists as well as foreigners — using sharp weapons and targeting the head or neck.
Al Qaeda in the Indian Subcontinent (AQIS) has reportedly claimed the murder of bloggers.
Security officials, however, claimed that local Islamist radicals were behind the murders and that messages from IS and AQIS were to cover the trail and confuse investigations and also claim presence where they did not have one.