A series of bomb blasts and shootings in northern Nigeria has killed at least five worshippers.

In the northwestern town of Kano, police say gunmen on a motorcycle killed five worshippers at a mosque Friday night. No one has claimed responsibility, but authorities believe Boko Haram is involved in the attack.

Authorities also suspect the radical Islamist group is behind bombings and gunfire that erupted in the northeast city of Gombe during evening prayers. There are no immediate reports of casualties.

Boko Haram has waged violent attacks in its campaign to implement strict Islamic law across Nigeria, which is roughly divided between Muslims in the north and Christians in the south.

The radical group claimed responsibility for one of the deadliest attacks in Kano last month that killed 185 people. The radical sect also admitted to killing at least 44 people in a Christmas Day bombing at a Catholic church outside Abuja, the capital.

Following the Christmas attack, President Goodluck Jonathan declared a state of emergency in areas hard hit by violence blamed on Boko Haram.

Mr. Jonathan said the measure impacted parts of Yobe and Borno states in the northeast, Plateau state in central Nigeria, and Niger state in the east.

He said the temporary closure of borders in those areas was necessary to address security challenges and restore normalcy to the country.

The opposition has criticized the Jonathan administration for failing to control Boko Haram.