Associated Press U.S. Marines stand guard at the American military compound at Kandahar airport yesterday. Activity at Kandahar airfield stepped up today as the military repaired bomb-damaged runways.

WASHINGTON - The bodies of six U.S. Marines killed in the war in Afghanistan were on their way home yesterday, and more than two dozen al-Qaida and Taliban prisoners were en route to detention in Cuba.

Military investigators continued to search the crash site in the rugged mountain area of southwest Pakistan for the last of the seven victims and clues to what caused the crash of the military refueling plane Wednesday.

"The search will continue," said Lt. Col. Martin Compton of the U.S. Central Command. "The Marines will leave no one behind."

A plane carrying the remains of the six arrived yesterday at the U.S. Rhine-Main Air Base in Germany, adjacent to Frankfurt's international airport. From there, they were to be taken to Dover Air Force Base in Delaware.

The names of those found were not released.

In the southern Afghan city of Kandahar, 30 prisoners departed for Guantanamo Bay in Cuba, three days after the first group of prisoners was transferred to the high security facility.

Shackled and with white caps covering their faces, they shuffled in the darkness late yesterday, Afghan time, into a C-17 transport plane for the flight to eastern Cuba. Lights at the U.S. base at the Kandahar airport were shut off except for red low-intensity lights and green chemical lighting. Security was tight, with attack dogs and Humvees with 50-caliber machine guns patrolling the area.

The first group of 20 detainees left Thursday and arrived in Guantanamo Bay the following day.

The base at the Kandahar airport is the site of the main detention center for al-Qaida and Taliban prisoners from the war. Officials said 464 were in U.S. custody altogether - 413 in Afghanistan, the 20 in Cuba, the 30 in transit and American John Walker Lindh on the USS Bataan in the Arabian Sea.

In Wednesday's crash, the seven were killed when their Marine KC-130 fuel tanker slammed into a mountainside and exploded while approaching an air base Americans have been using at Shamsi in southwestern Pakistan. Although U.S. forces in Pakistan have occasionally faced gunfire and other hostile actions, Defense Department officials say they have no evidence hostile fire brought down the plane.

Military officials also have said they have no indication that bad weather caused the crash, which caused an explosion that was seen and heard in a Pakistani town 20 miles away.

Also at the Kandahar base, an Army advance team from the 101st Airborne was preparing for the arrival of what officials said would be at least 2,000 more troops.

The Marines established and secured the Kandahar base and will be rotating out with the U.S. Army taking over responsibilities there.