A Pakistani decision to temporarily bar some trucks from a key passageway to Afghanistan threatened a critical supply route for U.S. and NATO troops on Sunday and raised more fears about deteriorating security in the militant-plagued border region.

The suspension of oil tankers and trucks carrying sealed containers came as U.S.-led coalition troops in eastern Afghanistan reported killing five Al Qaeda-linked fighters and detaining eight others, including a militant leader.

Al Qaeda and Taliban fighters are behind much of the escalating violence along the lengthy, porous Afghan-Pakistan border, and both nations have traded accusations that the other was not doing enough to keep militants out from its side.

The tensions come as violence in Afghanistan has reached its highest levels since the U.S.-led invasion ousted the Taliban regime in 2001 and as a surge in U.S. missile strikes on the Pakistani side of the border has prompted protests from Pakistan government leaders.

Last Monday, a band of militants hijacked around a dozen trucks whose load included Humvees headed to the foreign forces in Afghanistan. Renewed security concerns prompted officials to impose the temporary ban late Saturday, government official Bakhtiar Khan said. He said it could be lifted as early as Monday.

Lt. Cmdr. Walter Matthews, a spokesman for the U.S. military in Afghanistan, acknowledged only that "the appropriate authorities are coordinating security procedures."

"The convoys will continue flowing. We will not discuss when, or where, or what," he said.

Denied entry to the route, dozens of the trucks and oil tankers were parked along a main road near Peshawar, the regional capital.

Asked about security fears, Rehmatullah, a driver who gave only one name and said his truck was carrying a military vehicle of some sort, said, "This is our job, and we have to do it, but yes, we have a security risk every time we pass through the route."

Many of the supplies headed to foreign troops arrive in the southern Pakistani port city of Karachi in unmarked, sealed shipping containers and are loaded onto trucks for the journey either to the border town of Chaman or the primary route, through the famed Khyber Pass.

Last week's ambush took place at the entrance to the pass. Police said around 60 masked militants forced the convoy to stop briefly trading fire with nearby security officers. U.S. officials say the attackers seized two Humvees and a water truck. Several trucks carrying wheat for the World Food Program were also hijacked.

While critical of U.S. missile strikes in Pakistan's northwest tribal regions, both Pakistan's prime minister and president denied any plans to subvert the supply line as a pressure tactic in recent interviews with The Associated Press.

In Afghanistan, meanwhile, a U.S.-led coalition raid late Saturday in eastern Paktia province's Zurmat district nabbed and killed the Al Qaeda-associated insurgents, according to a military statement.

The detained Al Qaeda associated militant leader is accused of assisting the Taliban with the movement and training of Arab and other foreign fighters into Afghanistan, the coalition statement said without identifying him.

A homicide car bomber on Sunday struck a NATO convoy in the northern Baghlan province, killing one civilian and wounding 12 other people, officials said. Two NATO soldiers were among the wounded, said a spokesman for the force, who spoke on customary condition of anonymity.

In western Herat province Sunday, two U.S. troops were wounded when a homicide car bomber struck their convoy, said Col. Greg Julian, the spokesman for the U.S. military in Afghanistan.

In southern Afghanistan, a NATO soldier was killed by a roadside bomb Saturday, the military alliance said. It did not give the soldier's nationality or the exact location of the attack.

Also Saturday in eastern Khost province, coalition and Afghan troops detained a militant leader of the network led by an Afghan insurgent leader Jalaluddin Haqqani.

"During the combined operation, the force discovered 10 additional males believed to be militants and seeking safe haven as they move into Terezai district to conduct attacks," coalition statement said.

The United States once supported Jalaluddin Haqqani as a "freedom fighter" when he fought against the former Soviet Union's 1980s occupation of Afghanistan. He and his son Sirajuddin are now considered a main threat against U.S. forces and their allies in eastern Afghanistan.

Attacks in Afghanistan are up 30 percent from 2007, military officials say. More than 5,400 people — most of them militants — have died in insurgency-related violence this year, according to a tally of official figures provided to the AP.