Officials in northern Cameroon have ordered the closure of mosques and Islamic schools following a series of suicide bombing attacks that have left dozens dead.

Governor Midjiyawa Bakari said Sunday that he has ordered all street children to leave public places because all the suicide bombers so far have been under 18.

While there have been no claims of responsibility, authorities have blamed the Islamic extremist group Boko Haram, which has pledged its allegiance to the Islamic State group.

The group's leader has vowed to attack Cameroon because the Central African nation has aided neighboring Nigeria in its fight against the extremists.

In the latest attack inside Cameroon, at least 20 people were killed Saturday evening in the northern town of Maroua. The bombing came just days after another attack.