Unidentified gunmen on Wednesday killed two people and wounded five others at what appeared to be a peaceful demonstration in support of radical Shiite cleric Muqtada al-Sadr (search) in Kufa, northeast of Najaf, witnesses and hospital officials said.

Videotape from Associated Press Television News showed demonstrators wounded during a few minutes of heavy gunfire. It was unclear who was shooting.

Mohammed Abdul Kadhim, an employee at Kufa's Furat al-Awsat Hospital, said two marchers were killed and five wounded.

The marchers chanted slogans in support of al-Sadr and carried pictures of the cleric as well as pictures of Grand Ayatollah Ali Husseini al-Sistani (search).

The APTN videotape showed wounded men being carried away, and one man lying motionless in an ambulance as medics massaged his chest.

Witnesses said the gunfire appeared to come from an Iraqi National Guard (search) post, which sat behind concrete blast walls along the parade route.

The automatic weapons fire sent the marchers into a panic, with many scurrying for safety and yelling angrily. No one in the crowd could be seen firing a weapon, and it was unclear whether the incident was a gunbattle or an unprovoked attack on the demonstration.

Earlier Wednesday afternoon, Najaf Gov. Adnan al-Zurufi said Iraqi security forces had "taken all needed measures to prevent any crowds from entering the province," calling it a "military area."

The demonstration by hundreds of apparently unarmed al-Sadr supporters was headed to Najaf from the neighboring city of Kufa, with plans to break the U.S.-led siege there, witnesses said.

The demonstrators' chants praised al-Sadr and condemned interim Prime Minister Ayad Allawi (search).

"Allawi you are a coward. You are an American collaborator," the demonstrators chanted.

A U.S. military spokesman had no information on the incident.