NAJAF, Iraq -- A colonel from Saddam Hussein's most elite fighting force, the Special Republican Guard, has been training members of the Shi'ite militia battling U.S. forces in this holy city for more than two weeks.
His presence was tangible evidence of links between Sheik Muqtada al-Sadr's Mahdi's Army and fighters loyal to the ousted regime. Saddam's mainly Sunni officer corps and the Shi'ites who make up the Mahdi's Army long have been hostile to one another, but could cause more trouble for the government of Prime Minister Iyad Allawi by joining forces.
A U.S. military spokesman in Baghdad was reluctant to comment on links between Sheik al-Sadr's forces and the fighters in Fallujah.
"We have nothing that we can confirm at this time," he said.
The former colonel, Rifaat al-Janabi, was interviewed in a shaded corner of the green-and-gold Kufa mosque, where he had been training six Shi'ite fighters in the art of guerrilla warfare.
He said he and nine other officers from the Special Republican Guard had been sent to Najaf from Fallujah, the main Sunni flash point west of Baghdad.
"The Fallujah Consultancy Council of Mujahideen [holy warriors] sent me with nine other officers and 40 soldiers who are well-trained in using mortars and RPG-7 grenade launchers," said Col. al-Janabi, who, unlike most Iraqi insurgents, had no qualms about giving his name.
"We had to stand by our Shi'ite brothers in Najaf, who stood by us in Fallujah," he said.
That was a reference to aid provided by the Mahdi's Army during a major insurrection in Fallujah in the spring.
"It is an honorable stance of Fallujah people, who sent us experts in using weapons," said one Mahdi's Army militiaman. "We are in need of military training."
Indeed, although a few of the Mahdi's Army trainees had military training, many were inexperienced volunteers.
"I'm not a kid ... I can kill many Americans," said 13-year-old Hassan Kamel, a preparatory-school student who stood guard with his rifle at a checkpoint.
Outside the Mahdi's Army base in Najaf, Col. al-Janabi's fellow officers and soldiers from Fallujah could be seen drilling the Shi'ite militiamen in the use of RPG-7 grenade launchers.
"We welcomed the mujahideen of Fallujah who came, without being asked to come, to help us out in training the fighters who lack experience in using weapons," said Sheikh Kudair al-Ansari, who runs Sheik al-Sadr's office in Kufa, just outside Najaf.
While he spoke, militiamen swarmed around trucks unloading AK-47 assault rifles that had been smuggled into the city under a load of watermelons.
Minibuses from the southern towns of Amara, Kut and Diwaniya disgorged more young men who gathered outside the Kufa mosque and chanted: "By our blood and souls, we sacrifice for you, Muqtada."
Under Saddam's rule, Iraqis chanted the same slogan ending with the word "Saddam."
"I left a wife and three children to come and defend Muqtada," said one volunteer from Diwaniya, who refused to give his name. "We could not protect his father, Mohammed al-Sadr, from Saddam, but now we can protect his son from the Americans and the Jews."
The popularity of Sheik al-Sadr is built on the reputation of his father, a charismatic ayatollah who was killed in 1999 by assailants suspected of being Saddam agents.
During this week's fighting in Najaf, there also was evidence that some U.S.-trained police have been cooperating with the Mahdi's Army militiamen.
Near the mosque, four uniformed policemen were seen standing beside their car with three militiamen. Hidden behind a building, they were listening to their radios and informing the militiamen of their fellow officers' movements.
"I have four cousins in the Mahdi's Army," one of the police officers explained. "According to the proverb, 'My brother and I are against my cousin, but my cousin and I are against the foreigner.' Thus, I can't fight against my cousins and stand beside the Americans."
Soon after, one of the fighters ran into the street and shouted "Ali." He fired a rocket-propelled grenade at a concrete barrier erected by U.S. forces.
Then he ran back into the alley, climbed into the police car and was driven away.
Aqil Jabbar is a correspondent for the London-based Institute for War and Peace Reporting. Paul Martin in London contributed to this report.