Looters, Gunmen Fill Void of Somalia Pullout : Africa: U.N. peacekeepers abandon airport with U.S., Italian protection. Clan leader Aidid asserts control.

Crusted with garbage, festooned with litter, knee-deep in rusting junk, scavenged by packs of wild dogs, blown by dirty sand and scorched by unforgiving sun, a small part of this nation was given back to Somalis on Wednesday.

And they were happy to have it. Some slipped in early and hid overnight in abandoned boxes. Hundreds more assembled outside the fence.

Then, at dawn, as U.N. tanks retreated from the Mogadishu airport, Somalis swarmed in for a frenzy of looting and gunfighting. Bullets laced the sky. Explosions of rocket and grenade fire occasionally shook the ground.

“It’s not a good day to be tall,” said Army Sgt. Maj. Hank Callahan of El Paso, Tex. He knelt behind a berm of sandbags and watched the spectacle warily through the scope of his M-16 rifle.

On the high sand dunes east of the runway, along the edge of the Indian Ocean, American and Italian troops guarded the retreat, the second stage of a three-step process to extract the United Nations from the insoluble violence of Mogadishu’s clan warfare.

A Marine sniper killed a Somali gunman who fired a rocket-propelled grenade into the ocean behind American lines. Numerous other warning shots were fired from Marine and Italian positions to keep Somalis from trying to breech the razor-wire barriers. Otherwise, Americans were mere spectators who kept their heads down.

As of nightfall, two Marines and three journalists had been treated for minor sprains and cuts.

Casualties that Somalis inflicted on one another were not known, but surely greater. The U.N. retreat has severed most ordinary ties between the world and the hapless people of Mogadishu.

Even before dawn, the last of the peacekeepers--a Pakistani brigade--in the $2-billion U.N. effort began to form for retreat. First to leave were the infantry and all their equipment. Then platoons of tanks, turrets swung around and guns aimed to the rear, clattered down the main runway and slipped behind U.S.-Italian protective lines to be loaded aboard ships.

Looters instantly filled in behind the withdrawal. Some of the most eager dashed in between moving tanks. They grabbed bed frames, plywood sheets, rotting mattresses, rusty jerrycans and all variety of other U.N. castoffs. The booty was hoisted on heads, rolled or dragged toward home.

“Now, you’ve got to ask yourself: What does that young lady want with a 55-gallon drum?” observed Master Sgt. Dan Stoye of Ft. Campbell, Ky., an Army sniper peering through his telescope from a hill overlooking the airport.

Within 10 minutes, scattered shooting broke out from end to end of the vacated ground--Somalis quarreling with each other. Then came “technicals,” those sawed-off sedans and pickup trucks so common in Somalia, each topped with a machine gun, recoilless rifle or grenade launcher. And each loaded with militia.

Marine Lt. Gen. Anthony Zinni, commander of the U.N. withdrawal, had warned he would not let technicals approach his mission. But he chose to react cautiously with the heavy land, sea and air firepower he massed at the scene. A Marine sniper fired a warning shot near one technical. The gunner in the rear waved a friendly signal back.

Careering madly around corners, racing up and down taxiways, the technicals were not out to threaten the U.N. effort. Rather, it became apparent that one or another of Somalia’s warlords was moving in to claim a property that his nation had not controlled for 2 1/2 years. And the technicals were there to try to protect it against looters.

Shooting among the Somalis increased. To the south, technicals fought each other--a sure sign that one clan was challenging another for the prize property. Americans and Italians fired more warning shots from rifles and cannons as the fighting got too close. Stray Somali rounds whizzed over all the city. One group of Marines said they felt they were being deliberately targeted by Somali gunmen. Looting expanded.

Along the American lines, troops searched for words to describe the zany scene of this tragedy: A discount sale gone mad. An Easter egg hunt by the desperate. “It had a Keystone Kops appearance to it,” conceded Marine Col. Bucky Peterson, operations officer for the withdrawal.

A U.N.-financed Somali police force eventually moved in to try to bring order; in a nation where every boy and man is presumed to be armed, and nearly all are, the police carried only canes and sticks.

The commander of a U.S. sniper team watched the approach of a particularly menacing technical armed with a grenade launcher. “If he loads that thing and aims it this way, I want him gone, OK?”

The sniper took sight. But the technical turned to chase a band of looters.

By midday, shooting and looting both subsided as the Somali militia, technicals and the club-carrying police seemed to gain control of the airport.

It was a measure of the world’s remoteness from Mogadishu life that none of the Americans or U.N. officials here knew which of perhaps 10 independent clan militias had moved in.

At 3:30 p.m., the mystery was answered. A convoy of six technicals jounced to the north ramp of the airport and clan leader Mohammed Farah Aidid emerged from a car to survey his new property. Once hunted by U.S. troops as a war criminal, blamed for the deaths of 30 American soldiers during their deployment here in 1993, Aidid now strolled for an hour, inspecting buildings at the airport.

“Nope, he didn’t look up our way,” said commander Zinni, who watched through binoculars from a sandbagged bunker 300 yards away.

Curiously, the American may have aided Aidid in his conquest Wednesday. Those who watched the airport chaos agreed that the militia worked in concert with Somali police, who kept up communication links with Zinni’s command post. The general had vowed from the start of his mission not to take sides in the clans’ fighting.

Aidid then drove off as his technicals positioned themselves to defend their prize.

A repeat of this scene was considered likely today as American and Italian forces withdraw from the adjacent port and head back out to sea. If all goes well, the operation will conclude only three days after 1,800 American and 500 Italian troops came ashore.