Baghdad, Iraq ? A tentative peace agreement in the Najaf area faced its first test Friday when fighting erupted between U.S. troops and Mahdi militiamen loyal to Shiite cleric Muqtada al-Sadr, killing at least three Iraqis and wounding two American soldiers.

The violence came one day after both sides embraced a compromise aimed at stopping nearly two months of fighting in the holy city and the neighboring town of Kufa, where battles have killed several hundred Iraqis and damaged several shrines.

Najaf remained relatively quiet, but in Kufa U.S. forces faced three separate attacks with rocket-propelled grenades and small-arms fire as they conducted a reconnaissance operation, manned a traffic checkpoint and patrolled the city, officials said.

The U.S. base camp also came under mortar attack several times.

“While it has been quiet in Najaf, these would appear to be violations of that agreement that (al-Sadr) signed his name to,” said Brig. Gen. Mark Kimmitt, the senior military spokesman. “Now, these are small incidents that don’t seem to be endemic. … But we’ll wait and see, and we’ll continue to respond as and when necessary.”

A spokesman for L. Paul Bremer, civil administrator for the U.S.-led Coalition Provisional Authority, said he remained “cautiously optimistic” that the settlement would stick.

Al-Sadr representatives blamed U.S. troops for Friday’s bloodshed, saying American soldiers provoked the attacks by conducting patrols through the area and cutting off roads into the cities, preventing Shiites who had traveled to Najaf and Kufa from entering the cities to listen to Friday prayers.

“By these acts, they broke the truce,” said Sheik Ahmed Shibani, one of al-Sadr’s aides.

Al-Sadr did not deliver his prayer address Friday. His aides attributed his absence to security concerns. In recent weeks, al-Sadr has delivered a string of anti-American sermons, condemning the occupation.

In his place Friday, Sheik Jabr Alkhafaji called upon Najaf residents to rebel against U.S. forces.

“Unite in order to drive them from your country,” he said. “If America manages to eliminate the Mahdi Army, it will be the humiliation of everyone.”

Also Friday in Najaf, Sadr Din Kubanchi, a well-known cleric associated with the Supreme Council for Islamic Revolution in Iraq, was attacked by gunmen as he left a mosque after delivering a prayer.

One gunman was captured and witnesses said the suspect claimed to have been hired by al-Sadr’s militia. Al-Sadr’s office denied the claim and condemned the attack.