According to witness accounts, the gunmen have shot both Christians and Muslims in about ten villages.
"They killed indiscriminately," a witness said, according to AFP.
At least 500 people have fled the villages and sought shelter in larger communities.
No one has yet claimed responsibility for the attack, but the police suspect the local jihadist group Mahmuda.
Nigeria has recently seen an escalation of deadly violence in the northwestern parts of the country. According to the independent American organization ACLED (Armed Conflict Location & Event Data), jihadist groups with links to al-Qaeda and ISIS are primarily behind the violence.
On Wednesday, the US embassy announced that all non-essential personnel were allowed to leave the country due to the security situation.
