MOSUL, Iraq, 13 April 2003 — The Kurdish guerrillas wandering the streets looked lost, and at times scared, in a city they had entered as strangers.

They had taken this city Friday, along with US Special Forces troops, without a fight. The guerrillas were strangers in Mosul, Iraq’s third largest city, because the population here is almost completely Arab, primarily Sunni Muslim. Though the Sunnis are a minority in Iraq, they prospered under Saddam Hussein’s Baath Party rule. They now have the most to lose as his regime crumbles.

Most people hid in their homes as looters and armed thugs roamed the lawless streets. What little policing there was fell to the lightly armed Kurdish guerrillas who had fought their way here from the north. US soldiers were nowhere to be seen except at checkpoints on Mosul’s outskirts.

Near the construction site of a huge mosque that Saddam Hussein was building as another monument to himself, two Arab men seethed with anger at Mosul’s chaos.

“They even stole from this mosque, the cars and computers of the engineers, all sorts of equipment,’’ said one of the men. “We think that America has encouraged people to do that.’’

The men, a mechanical engineer and food factory owner, live in a wealthy district of Mosul, and obviously benefited from Baathist rule.

“Americans won’t be allowed here because they are not part of this region,’’ said one. “We don’t want them to win our trust.’’

Yasir Adil Taka, a neurosurgeon, questioned the strategy of removing the city’s government and security forces without having a proper force to fill the power vacuum.

“This is not freedom,’’ said Taka, head of neurosurgery in the children’s ward at Ibn Sina Teaching Hospital. “This is just bad ethics. If they wanted to change the government, there were other means to do that. This wasn’t needed. It is criminal.’’

Just down the street from the ruins of ancient Nineveh, where an Assyrian king built one of civilization’s most admired libraries 600 years before Christ, Kurdish fighters in two pickups and a sedan escaped from a drive-by shooter Friday afternoon. One of the guerrillas kept the rear door propped open, his Kalashnikov ready to fire, as their small convoy made its escape.

“People are shooting at us,’’ another guerrilla shouted at a passing car, before careening through an intersection. “It’s better to stay away!’’

At another major crossroads, next to the bombed-out ruins of the Mosul government irrigation office, a car full of local gunmen in civilian clothes drove head-on at a small group of Kurds, firing in all directions as they approached. Most of the Kurds ran for cover, but a few stormed the car and arrested the men.

At Friday prayers, imams urged Mosul’s youth to defend their neighborhoods. One young man took up the call with an iron bar, which he used to stop cars and warn against looting. Miles away from Mosul, Kurdish guerrillas set up checkpoints to keep looters from streaming into the city, as they did by the thousands when Kirkuk fell Thursday.

But the lure of booty was too strong, and many used smugglers’ dirt tracks to evade the cordons. And many more looters came from Mosul itself.

They included children who helped adults ransack the education directorate building. One boy playfully tossed reams of students’ files, exam papers and other ministry documents into the air as he stood in front of a giant mosaic tile portrait of a smirking Saddam Hussein.

Plunderers also attacked Mosul’s university, a luxury hotel, the city’s branch of Iraq’s central bank, numerous police stations and one of Saddam’s many palaces.

As if Iraq needed more guns in civilian hands, the looters also struck gold at the abandoned Iraqi Army Fifth Corps’ sprawling base, where they walked off with assault rifles, rocket propelled grenade launchers and assorted ammunition by the armful.

Most took a pass on the new Iraqi Army berets, boots and uniforms.

The sidewalk in front of the burning central bank building was littered with the shredded remains of photocopied Iraqi dinars, the only legal tender currency since Saddam banned the use of regular bank notes following his defeat in the 1991 Gulf War.

As gunmen fired into the air, people still risked their lives to get into the bank’s vault and carry out armfuls of the photocopied cash that is now virtually worthless.

Even if they could persuade a store owner to accept a dead regime’s phony money at a discount, all shops were shuttered tightly shut Friday.

During three weeks of bombing, the Ibn Sina Hospital treated 15 wounded children, four of whom died. More than 40 patients died from bombing injuries at Ibn Sina, out of some 140 killed in the city, said anesthesiologist Usama Shamsaddin Aziz. At least a dozen gunshot victims, including a wounded child, were treated Friday, and hospital spokesman Hussein Ali Agha Sulayman said Friday’s unrest was harder to take than the relentless bombing.

“This is more difficult because we see people are stealing and taking other people’s property,’’ he said.

Hospital staff were sleeping in the complex to defend it from looters and they chased off a car thief Thursday night. But they won’t be able to stop armed, determined attackers.

The only solution, Sulayman said, is to bring in US troops — and fast.