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Three Marines injured in blast

KANDAHAR, Afghanistan (CNN) -- Three U.S. Marines injured Thursday while burning trash at their base camp in Kandahar have been taken to a higher-level treatment facility in an undisclosed location.

One Marine suffered extensive injuries to his upper torso and had surgery at the Kandahar airport before being transported. His wounds were not life-threatening, military officials said.

Another suffered superficial chest and arm injuries, and another was injured near his eye.

All three, from the 26th Marine Expeditionary Unit, were hurt when an unknown item exploded in a burn pit while they were burning trash, the U.S. Central Command said. Their names were being withheld pending notification of their next of kin.

Friday was the last full day of U.S. Marine patrols at the Kandahar airport as the U.S. Army prepared to assume full command of the facility.

There will be no ceremony when the handover takes place Saturday at 8:30 a.m. (11 p.m. Friday ET), military officials said.

About 3,600 are in the Marine-Army coalition at the airport. Of those, 800 are Army troops, a number that grows every day.

On Thursday, a group of 30 detainees was transported from Kandahar to Pakistan, lowering the total number of al Qaeda and Taliban prisoners being held at the airport facility to 290.

A spokesman for the U.S. Central Command in Tampa, Florida, said all 30 were Pakistani citizens who did not meet "screening criteria" for transportation to Guantanamo, Cuba, where a total of 110 people are being held.

"The screening criteria that we use has to do with their activities or their association with al Qaeda and the Taliban and the possible threat that those individuals would pose to U.S. citizens should they be released," said Maj. Pete Mitchell.

He said he did not know what the Pakistani government planned to do with the detainees once they were repatriated.

"It is a sovereign nation," Mitchell said. "These are Pakistani citizens ... and it was deemed possible that these people could be repatriated to their governments of origin."

The 30 Pakistanis, said Mitchell, were among many who crossed the border into Afghanistan to fight in what they thought was a jihad when the U.S.-led campaign began. Disillusioned by the Taliban's views, many of them laid down their arms and returned home to Pakistan.

Also Thursday, local citizens approached one of the Marine patrols at Kandahar airport to say they had returned home from a trip to find someone had stored ordnance in their house. The locals asked the Marines to remove it.

In what U.S. military officials described as an example of continuing cooperation between local citizens and the military, the Marines took out the ordnance and destroyed it in a controlled explosion Thursday evening.

Further details about the ordnance were not disclosed.