NAJAF, Iraq (AP) - Five American peace activists, who are carrying U.S.-troops-go-home banners through militia-controlled streets, said Friday they hoped their presence would help prevent an assault on this holiest of Shiite cities by U.S. forces.

"We want to let the U.S. military know that if they launched an attack on the citizens of Najaf there would also be American citizens with them," said Peter Lumsdaine, member of an ad hoc peace delegation, which arrived in this tense city a week ago.

Lumsdaine said he would probably unfurl his banner in the face of any U.S. troops moving into the core of the city. But the group didn't appear to have a concrete plan.

Najaf and the neighboring city of Kufa, including two sacred mosques, were seized by followers of radical cleric Muqtada al-Sadr April 4, and negotiations for a peaceful end to the crisis have dragged on since.

U.S. forces ring the twin cities and have stationed more than 200 troops within the metropolitan area. But commanders say they realize an attack on the sacred sites, where al-Sadr is headquartered, would likely create a powerful backlash throughout the Muslim world.

The group said they felt safe inside Najaf and had been warmly welcomed by ordinary citizens as well as representatives of al-Sadr and Grand Ayatollah Ali al-Husseini al-Sistani, the moderate religious leader who commands the widest following among Iraqi Shiites.

Al-Sadr's group, which they described as "calm, informative and supportive," offered them bodyguards but they declined.

"It's safer to be an American without weapons in Iraq than one with a gun," said Bryan Buckley, a Catholic Church relief worker from Louisa, Va.

"The people in Najaf have been so hospitable. They've just opened their hearts to us, especially as they find out that we are here to confront our military. They offer us tea and support and smiles from ear to ear," said Peter's wife Margaret, a Lutheran pastor from Santa Cruz, Calif.

She said residents would honk their car horns and cheer when they saw them carrying a placard reading "USA don't be the new Saddam. Come Home" and "No to the American occupation."

Margaret also met earlier in the week with U.S. commanders and coalition officials just as a mortar attack was launched on their base, located four miles from the main mosque.