Iraq's top Shi'ite cleric, Ayatollah Ali al-Sistani, returned home to Najaf Thursday, along with thousands of demonstrators, in a bid to end a bloody three-week uprising by radical Shi'ite cleric Moqtada al-Sadr. Late in the day, his aides announced a peace deal had been reached.

An aide to rebel cleric Moqtada al-Sadr says a peace deal has been reached to end a three-week uprising by al-Sadr militants, known as the Mahdi army.

The terms of the five-point deal include declaring Najaf and nearby Kufa weapons-free zones and moving foreign forces out of the area. Al-Sadr militants will disarm and security will be left to the Iraqi police. The government will also pay compensation to victims of the fighting.

Grand Ayatollah Ali al-Sistani clinched the peace agreement less than 24 hours after returning to Najaf from London where he had been treated for a heart ailment.

Prime Minister Iyad Allawi had ordered a 24-hour ceasefire while Ayatollah Sistani held peace talks with Moqtada al-Sadr's representatives.

The announcement is being greeted with cautious optimism. Previous peace bids brokered by the interim government have not lasted but Ayatollah Sistani does wield enormous influence among Iraqi Shi'ites.

Earlier Thursday, tens of thousands of Shi'ite demonstrators responded to Ayatollah Sistani's call to march to the holy Imam Ali shrine in Najaf to try to end a siege there. Militants loyal to firebrand cleric al-Sadr have been holed up for three weeks inside the shrine.

U.S. and Iraqi forces have been locked in battle with the militants for control of Najaf, inflicting heavy civilian casualties and property damage.

Tragedy also struck in nearby Kufa Thursday when a mortar attack killed more than 70 Shi'ite demonstrators and wounded more than 300 others.

In other news, smoke still billowed Thursday from several burning oil pipelines after they were hit by saboteurs late Wednesday. Oil exports are reported to have been cut by a third.

And, a militant group calling itself 'Black Banners Division of the Secret Army' says it will release seven employees of a Kuwaiti company when the company leaves Iraq. The group has dropped its other demands.