A suicide car bomber attacked an office of a major Kurdish party Wednesday, killing or injuring at least 20 people, an official of the Kurdistan Democratic Party (search) said.

The attack occurred at the KDP office in the town of Sinjar, three miles southwest of Mosul, KDP official Mahdi al-Harki (search) said.

"Twenty people were killed or wounded in the suicide attack," al-Harki said, adding that the explosion caused major damage to the building. He had no further details.

The KDP is one of the two largest Kurdish groups in Iraq and strongly supports holding Sunday's general elections on schedule. The KDP is part of a coalition of 11 Kurdish groups for the elections. The second group is the Patriotic Union of Kurdistan (search).

Earlier in the day, assailants blasted a building that houses a PUK office with heavy machine gun fire in the central city of Baqouba.