A suicide car bombing followed by an assault by grenade-throwing gunmen on a police headquarters in a disputed city in north Iraq killed 30 people on Sunday

A suicide car bombing followed by an assault by grenade-throwing gunmen on a police headquarters in a disputed city in north Iraq killed 30 people on Sunday.
  
The vehicle that was detonated in central Kirkuk was painted to appear as though it was a police car, and the militants who sought to seize the compound were dressed as policemen, witnesses said.
  
The attack shattered a relative calm in recent days in Iraq, which has been grappling with weeks of protests against the Iraqi government, less than three months before key provincial elections.
  
No organization immediately claimed responsibility for the attack.
  
The initial suicide car bomb was set off during morning rush hour, and was quickly followed by three gunmen dressed in police uniforms, armed with hand grenades and suicide vests, bursting through the main gate of the Kirkuk police compound in the direction of the headquarters building.
  
They threw multiple grenades as they sought to reach the building, but were killed before they could get there, witnesses said.
  
Brigadier General Natah Mohammed Sabr, the head of Kirkuk city's emergency services department, put the toll at 30 dead and 70 wounded.
  
In addition to the casualties, the attack caused massive damage to nearby buildings and shops, according to an AFP journalist at the scene.
  
The massive explosion also killed people in nearby buildings. Mohammed Aziz, who works in an office building adjacent to the police headquarters, said at least two of his colleagues died in the blast.