Police in Kirkuk say a driver in a car packed with explosives approached a checkpoint near the headquarters of the Patriotic Union of Kurdistan.

The bomber blew himself up 200 meters away from the building, flattening the walls of the compound and shattering windows at a nearby primary school.

Kurdish militiamen guarding the headquarters immediately apprehended four suspects in the area of the blast.

The leader of the Kurdish party, Jalal Talabani, holds the rotating presidency of Iraq's Interim Governing Council this month. Mr. Talabani was in neighboring Turkey on an official visit.

Several-hours earlier, a car bomb exploded outside the home of a powerful tribal leader in the town of Ramadi, west of Baghdad. Sheik Amer Ali Suleiman was not injured in the blast, but at least two of his relatives have reportedly been killed.

Mr. Suleiman is the leader of the Duleim tribe, one of the largest Sunni Muslim tribes in Iraq. He has been working closely with coalition officials and is a member of the U.S.-supervised city council in Ramadi.

The incident was one of five anti-coalition attacks to hit Ramadi on Wednesday. The commander of U.S. forces in the area had been considering handing over security responsibilities to the Ramadi police in the next two months, because of improving security there.

Ramadi lies in the so-called Sunni Triangle where U.S. forces have come under numerous daily attacks since they arrived in late April.

Meanwhile, in the southern city of Basra, representatives of the Assyrian Democratic Movement party say one of its members on the local pro-coalition municipal council has been abducted and killed. A statement from the group says Sargoun Nanou Murado was kidnapped Tuesday on his way to work. His body was discovered a day later.

The assassination is the second time this week an Iraqi working with coalition authorities has been killed in southern Iraq. On Tuesday, gunmen shot and killed the Education Ministry's director general for Diwaniyah province.