Gunmen wearing suicide vests stormed two police stations in Samarra, about 100 km north of the Iraqi capital Baghdad, killing at least seven police officers.

Security sources said multiple gunmen took over the police stations in an attack at night time, before Iraqi forces were able to regain control.

The mayor of Samarra said security forces had killed at least six assailants, but declined to comment on the number of casualties on the government side.

The Pro-Islamic State news agency, Amaq, said the militants had executed some policemen.