Nigeria’s military on Wednesday claimed that more than 300 Boko Haram fighters were killed when troops recaptured the garrison town of Monguno in northeast Borno state.

“Over 300 terrorists were killed while a few were also captured,” defence spokesman Chris Olukolade said in an emailed statement.

There was no independent verification of the claims, which follow similar assertions about Boko Haram casualties by Niger, Chad and Cameroon involved in the regional fight-back against the militants.

Nigeria’s claim came as the Islamist group vowed to make voting impossible in the upcoming election after a spate of deadly attacks in the violence-wracked northeast.

The group’s leader Abubakar Shekau said in a new video posted on Twitter late on Tuesday evening that his fighters would disrupt polling scheduled for March 28.

“This election will not be held even if we are dead. Even if we are not alive, Allah will never allow you to do it,” he said in the Hausa language widely spoken in northern Nigeria.

Shekau also claimed responsibility for a large-scale attack on the northeastern city of Gombe last Saturday where leaflets were dropped warning people not to vote.