Six members of the security forces were killed along with two Iranians who were part of a team carrying out maintenance in a power station outside the city.
At least eight militants were also killed either by blowing themselves up or in clashes with the security forces.
Kurdish forces had dislodged the militants from all the buildings they had seized except a hotel and a mosque where fighting continued.
A curfew has been declared in the oil city as residents reportedly confirm hearing explosions since one a:m.
Meanwhile; the Islamic State has claimed responsibility for the attacks in online statements.
