Police in northern Nigeria said Boko Haram militants have opened fire at a funeral in Adamawa state, killing at least 18 mourners.

Authorities also said many others were injured in the attack on Kuda village, outside Madagali and that the death toll could rise.

Witnesses said the Islamist militants stormed the village on motorbikes and opened fire on the mourners observing a wake. They said many of the victims were women and children.

Boko Haram is blamed for some 20,000 deaths since beginning its insurgency in northern Nigeria in 2009. The Islamist extremist group says it wants to create a strict Islamic state in Muslim-majority northern Nigeria.

Last year, the Nigerian army was able to retake most of the territory captured by Boko Haram in recent years with the help of neighboring countries; but, the group has continued to attack markets and public places, often using female suicide bombers.