5 Afghans stopped near Kandahar base

KANDAHAR, Afghanistan (CNN) -- Military officials detained five Afghans suspected of trying to cross a U.S. Army base perimeter Saturday, but four were released when officials determined they were children collecting firewood, authorities said.

A man believed to have been under the influence of drugs was still being held.

U.S. soldiers guarding the Kandahar airport perimeter apprehended the man as he tried to cross the barbed-wire fence about 6 p.m. (8:30 a.m. EST), according to Col. Frank Wiercinski.

About an hour later, the youngsters were spotted moving toward the fence near the same area where the man was found. Soldiers fired flares into the air to illuminate the area, and took them into custody for questioning, Wiercinski said.

As a precaution during the incidents, the entire base was placed on full alert. Helicopters patrolled the immediate air space and takeoffs were delayed for a C-17 transport plane and a C-130 cargo plane.

Soldiers have reported seeing people moving around the perimeter, and evidence of weapons has been found around the airfield in recent weeks, prompting officials to expand the security perimeter and increase the number of security patrols.

Earlier this month, between eight and 14 snipers penetrated the airport's outer perimeter, which is guarded by local opposition groups, as a transport plane carried the first group of detainees to Guantanamo Bay, Cuba. No one was injured in the firefight, which lasted about 10 minutes.

The inner perimeter surrounds the base directly and is guarded by U.S. forces.