Four worshippers were killed in a suicide bombing at a mosque in northern Cameroon on Monday, a security source said, five days after a similar attack left 12 people dead.

Monday's attack took place in the village of Nguetchewe in an area regularly targeted by Boko Haram.

"The toll of this attack is four dead and two injured," the source, who was at the scene of the attack, told AFP on condition of anonymity.