Nigeria's police in northwest Kano State on Tuesday said gunmen riding on motorcycles attacked a primary school in the metropolis, injuring at least three teachers.

State commissioner of police Musa Daura disclosed this to reporters in Kano, the state capital.

The gunmen were said to have attacked Dan Maliki primary school in Kumbotso Local Government of Kano between 9:30 a.m. local time and 10:00 a.m, local time while pupils were in class.

A security source told Xinhua that two teachers and the headmaster were wounded.

The teachers have been treated and discharged but the police said the headmaster is still receiving medical attention.

Kano State has witnessed waves of violence. Thousands of people have been killed in northern and central parts of Nigeria.