The unknown person made a phone call to the room of the department chairman at 11:45am and threatened to kill the teachers if they take part in the election to the Dhaka University Teachers' Association (DUTA), scheduled for December 21, says a press release.

Prof Sharifullah Bhuiyan and Prof Muntasir Mamun are contesting the DUTA election as candidates of the opposition-backed Blue and Pink joint panel for the posts of president and executive member.

In separate statements, the DUTA and the Pink panel expressed grave concern over the death threats.

They also demanded immediate steps to ensure security of the teachers.

A general diary has been filed with the Ramna Police Station in this connection, police said.