Six police officers were killed and six others wounded in an attack by militants of the Islamic State (IS) group in Iraq's Salahudin province, north of Baghdad, a provincial police source said on Wednesday.

The attack took place late Tuesday night when IS militants attacked a base of the federal police in the Mteibijah area in the eastern part of the province, sparking a fierce clash between the two sides, Captain Yousif al-Zaidi said.

There were no immediate reports about casualties among the extremist militants who fled the scene after reinforcement troops arrived, al-Zaidi mentioned.