Iraqi and American troops are searching a mostly Sunni town in Babil province for the attackers who dressed in American uniforms and stormed a Joint Coordination Center in Karbala on Saturday, killing five U.S. soldiers and wounding three others.

The town of Elbu Alwan, about 20 miles north of Karbala, is an area in Babil where insurgent groups have operated before, officials said Monday. Four of the sport utility vehicles used in the attack were found there Sunday, officials said Monday.

According to details released Monday, the attack was carried out by men disguised in American uniforms, body armor and carrying official-looking documents. The men were waved through one Iraqi checkpoint at the city’s edge by security forces who apparently assumed the SUVs carried American officials. The convoy sped through several others unchecked, sometimes firing warning shots, officials said.

The attack took place during a security planning meeting between American military officials and local Iraqi officials dealing with the Shiite pilgrimage of Ashura, when thousands will visit Karbala, said Lt. Col. Scott Bleich- wehl, a spokesman for Multi-National Division — Baghdad.

According to Iraqi officials, at least one of the vehicles had a sign in English and Arabic on its back window warning drivers to stay back from the convoy — similar signs are sometimes used on both American military and civilian vehicles. Iraqi police said bags with American clothing, guns and body armor were found in the abandoned vehicles used in the attack. Babil police officials said some of the attackers had beards, which U.S. soldiers do not wear by regulation.

American military officials said no troops were missing after the attack, which lasted around 20 minutes and involved grenades, small-arms and indirect fire.

Three bodies — believed to be those of attackers killed during the raid — were found in the abandoned vehicles.

“The way it happened and the new style, the province has not seen before,” Abdul al-Yasri, head of the provincial council in Karbala, was quoted as saying in The Washington Post. “And this will make us insist on carrying on the security procedures even on official delegates and diplomats when they are coming to Karbala province.”