Helicopter gunships destroyed a training camp for suicide bombers in northwestern Pakistan's troubled Swat Valley overnight, killing six suspected Taliban fighters, the army said Saturday.

The camp's trainees — including teenagers — were responsible for at least three attacks in recent weeks, an army spokesman said.

The raid on the training facility, located on a small island in the Swat River opposite the town of Charbagh, came Friday night after local residents tipped off security forces of its location, according to Lt. Col. Akhtar Abbas, the army spokesman in Swat.

Intelligence reports linked the camp to attacks that killed a total of 10 soldiers and civilians this month, he said. Two of the attacks took place last weekend near Mingora, the valley's main town, and another was earlier this month in a more remote area.

"We have been working to find their source, and today we destroyed that source," Abbas told The Associated Press.

Abbas said another six militants were killed in two separate operations elsewhere in Swat. In one operation, five Taliban fighters were killed, including a close aid to a high-ranking Taliban commander, Shah Doraan.

The officer said military operations were weakening the Taliban, and that many had chosen to turn themselves in rather than fight.

"With every day passing, the noose is being tightened around them, and that's why more and more of them are opting to surrender," Abbas said.

Separately, the army said it had arrested another 11 suspected militants in separate search operations in the region.

Security forces have been winding down a nearly three-month offensive to dislodge the Taliban from the Swat Valley and surrounding areas, but sporadic clashes continue. The army has also been accused of carrying out extra-judicial killings of suspected Taliban and then dumping their bodies on streets in towns around Swat. Security forces have strongly denied the allegations.

The United Nations said this past week that about 1.5 million people who had fled fighting in the wider region were returning home, and the World Health Organization said it was concerned about providing health support for them.

Authorities also have been battling militants in Pakistan's lawless and remote tribal belt along its northwestern border with Afghanistan.

Two intelligence and a government official said one militant was killed and another captured during an attack on a security checkpoint that wounded a soldier in the North Waziristan tribal region.

The officials, who spoke on condition of anonymity because they were not authorized to release the information to media, said an unspecified number of militants in a car attacked the checkpoint on a main road linking the area to South Waziristan, the heartland of Taliban.

Police were investigating the possible Al Qaeda links of 12 suspected foreign militants arrested Friday on the edge of the tribal area, after they allegedly sneaked into the country from Iran, Punjab provincial police official Mohamad Rizwan said.

"One thing is certain, that they are terrorists," Rizwan said.

The men from Sudan, Russia, Turkey and Iran were arrested in the city of Dera Ghazi Khan, said Hassan Iqbal, a district official. Police also seized a laptop computer and $10,000 from the men, he said.

The detainees "had links with Taliban" and wanted to go to Pakistan's South Waziristan tribal region, Iqbal said, without giving further details.

South Waziristan is a stronghold of former Pakistani Taliban commander Baitullah Mehsud, who was killed by a CIA missile strike earlier this month.

Pakistan has deployed more than 100,000 troops in the tribal regions since the Sept. 11, 2001, attacks in the United States. Authorities have arrested about 1,000 Taliban and Al Qaeda suspects over the past few years, including senior aides to Al Qaeda chief Osama bin Laden and his deputy, Ayman al-Zawahri.

Al-Zawahri, in a video posted Thursday on Islamic militant Web sites, said a Pakistani offensive against the Taliban in the Swat Valley was doomed to fail. He urged Pakistanis to "back the jihad (holy war) and mujahedeen" with fighters, money and support.