At least 25 civilians and members of government forces have been killed in northern Iraq since late Sunday in attacks by the Islamic State group, officials said.

A police officer told AFP that IS militants killed 15 people at a fake roadblock on a major highway in Kirkuk province, north of Baghdad. Another IS attack in the same province killed three others, the officer said.

In the Mosul region, seven people, including the mayor of a village, were killed by IS assailants disguised as soldiers, a local official said.

The attacks came despite Baghdad's declaration of victory over the militant group last year.