At least eight people were killed Tuesday night at a beer parlor in the northeastern state of Yobe, said Nigerian authorities.

The tragedy occurred when gunmen opened fire at customers in the bar, leaving eight people dead, including a few police officers, said state police commissioner Tanko Lawan.

He said investigation was already under way.

Local media reported that the gunmen were of the Boko Haram extremist group, which claimed responsibility for the recent Christmas Day attacks that killed more than 40 people.

Earlier Tuesday, five people were killed in an attack in a mosque in the Christian-dominated southeastern state of Edo, as the nationwide strike against the removal of fuel subsidy entered the second day.

A state of emergency has been imposed in areas targeted by the Boko Haram sect, including Yobe, Borno, Plateau and Niger states.