An unusual wave of attacks has been happening in northern Nigeria.

More than 30 cell phone towers have been targeted.

Nigeria has very few functioning landlines, so cell phones provide a key communications link.

Friday, the militant Islamist group Boko Haram claimed responsibility for attacking the towers.

The group is trying to create a hard-line Islamic state in northern Nigeria.

It previously bombed government offices, schools and other public buildings in the region.

The BBC’s Sam Olukoya tells anchor Lisa Mullins cell phone operators are threatening to pull out of the region.