Associated Press Afghans read flyers seeking information about al-Qaida members and Taliban authorities after receiving them from U.S. Marines on patrol outside of the American military compound near Kandahar, Afghanistan yesterday. More than three months after the beginning of American offensive in Afghanistan, most of the high-ranking Taliban and al-Qaida officials still remain at large.

KANDAHAR, Afghanistan - U.S. Marines began an extraordinary security mission yesterday night - flying the first of hundreds of al-Qaida prisoners to a U.S. base on Cuba, where they are to be held for questioning and possible trial.

Gunfire broke out near the heavily guarded Marine base at Kandahar airport as the U.S. Air Force C-17 took off - a sign of how the area around the city that was once a stronghold of the Taliban remains insecure.

Shortly after the aircraft left the runway, the base received small arms fire, and Marines responded with heavy outgoing fire, Marine Lt. James Jarvis told The Associated Press<. He said he knew of no U.S. casualties in the firefight, which witnesses said lasted about a half-hour.

The prisoners are being taken to the American base at Guantanamo Bay, Cuba and the U.S. military is taking no chances with them since other al-Qaida and Taliban fighters captured in the Afghan conflict have staged bloody uprisings against their captors.

"These are dangerous individuals," Defense Secretary Donald H. Rumsfeld said in Washington yesterday. "There are among these prisoners people who are perfectly willing to kill themselves and kill other people." He said those overseeing the transfer have been told to use "appropriate restraint."

During the flights to Cuba, prisoners were to be chained to their seats - and possibly be sedated, forced to use portable urinals and be fed by their guards - according to USA Today and television reports.

The exchange of fire at the base brought U.S. warplanes out hours later patrolling around Kandahar, a rare event since U.S. bombing ended in the area. To the north of the base lies a highway running parallel to the east-west runway. Mud houses on the other side of the road provide some of the only cover in the area; the rest of the base is surrounded by bare fields, a few houses and an old mine field.

Although the Taliban lost control of Kandahar and other major Afghan cities under the combined assault of U.S. airstrikes and offensives by Afghan fighters, security in the country is tentative at best. Many of the deposed militia's fighters have disappeared into Afghanistan's rugged terrain or have blended into civilian populations.

In the capital, Kabul, British peacekeeping forces and newly deputized Afghan police yesterday formally launched joint patrols of the city in an effort to restore security and civilians' trust. The new Afghan government has ordered men with guns off the city streets.

There were fewer weapons seen in Kabul yesterday, but occasional pickup trucks crammed with men with rocket launchers and automatic rifles still roared through the streets. Men in camouflage uniforms, apparently soldiers, still were out despite being ordered to return to their barracks.

Meanwhile, Pakistani and U.S. recovery teams converged on the crash site of a Marine KC-130 refueling tanker that struck a mountain near a remote base in Pakistan near the Afghan border and exploded in flames Wednesday. Seven Marines were killed, the worst American casualty toll of the Afghan war.

The base - in the southwestern Baluchistan province of vast deserts and rugged mountains - has been used by the U.S. military as a forward staging point. U.S. officials said there was no indication the plane was hit by hostile fire.

In other developments:

- U.S. warplanes struck again early yesterday at the huge cave, tunnel and building complex used as an al-Qaida training camp in the Khost region of eastern Afghanistan.

- Britain said it would lead the international peacekeeping force in Afghanistan for only the first three months, with Turkey a candidate to take over after that.

While the U.S. forces began the shipment of prisoners to Cuba, U.S. and Afghan officials were distressed that some top Taliban officials were captured and then set free - among them Mullah Nooruddin Turabi, who led the campaign to destroy two giant sandstone statues of Buddha.

Turabi and six other senior Taliban figures surrendered to Gul Agha, the governor of Kandahar. Agha took Turabi's vehicles and weapons and then let him go without informing either the Kabul government or the United States.

"A leader like Turabi shouldn't have been released. It's not for a local leader to decide this issue," Foreign Minister Abdullah, who uses one name, told AP yesterday.

"We want any of the high-ranking Taliban or al-Qaida," said Jarvis, the Marines spokesman. "We want to have them in custody."

Anti-Taliban Afghan forces have steadily been turning over captured al-Qaida members to the Marines, and more have come from Pakistani troops intercepting fugitives trying to flee across the border from the bombed-out mountain hideouts at Tora Bora and Khost in eastern Afghanistan.

Jarvis said yesterday that 45 new prisoners arrived at Kandahar airport overnight, bringing the total there to 351. U.S. officials have not said the total number of prisoners that will be taken to Guantanamo.

At Guantanamo Bay Naval Station in Cuba, a temporary detention area called Camp X-Ray has room for 100 prisoners and soon could house 220. A more permanent site under construction is expected to house up to 2,000.

There, prisoners will be isolated in individual, open-air fenced cells with metal roofs. They will sleep on mats under halogen floodlights. They could get wet from rain, but officials say they will be treated humanely. The Red Cross and other organizations will monitor conditions.

The name of the camp where the detainees are to be held, Camp X-ray, dates from the 1990s, when Haitian and Cuban migrants were held at the base, said base spokesman Chief Petty Officer Richard Evans.

The name's precise origin is unclear, although other camps also set up during that time had call-sign names such as Alpha, Beta and Charlie, Evans said. Employees still use such names for areas of the base, even though the tent cities that housed the Haitians and Cubans have disappeared.