QUETTA, Pakistan - Police say three supporters of Pakistan opposition leader Benazir Bhutto were killed today when gunmen attacked her party's office in a town in southwestern Pakistan.

The attack occurred in Naseerabad.

District Police Chief Wajid Akbar says he has no immediate information about the motive for the attack or who was behind it. The bloodshed is the first such incident in the campaign for parliamentary elections scheduled for Jan. 8.

Pakistan has been engulfed in a political crisis since Nov. 3, when President Pervez Musharraf imposed emergency rule and fired Supreme Court justices who were preparing to rule on the validity of his October re-election.

Since then, Bhutto and another former prime minister, Nawaz Sharif, whose government was ousted by Musharraf in a coup in 1999 - have been trying to reach agreement on a set of demands that would allow their two parties to participate in the ballot.

Both have accused Musharraf, who retired from the army last month before being sworn in as a civilian president, of planning to rig the elections.