AP -- A tanker carrying oil for NATO forces in Afghanistan exploded Saturday in northwestern Pakistan as people tried to siphon off some of its fuel, and 15 were killed, an official said. Separately, 14 NATO tankers were damaged in a bombing at a nearby border town, but no one was hurt.

The incidents underscored the dangers linked to the vehicles that carry non-lethal supplies for Western troops in Afghanistan through Pakistan. Such convoys frequently face bombings and other attacks by Taliban and other militants, as well as ordinary criminals, and many Pakistani civilians get hurt as a result.

Both incidents occurred early in the day in Pakistan's Khyber tribal region, an area where numerous trucks carrying supplies for U.S. and NATO forces in Afghanistan must traverse, local administrator Abdul Nabi Khan said.

In the Landi Kotal area of Khyber, a tanker first caught fire. After it appeared the blaze was under control, people tried to take the tanker's fuel. Then the blast occurred, killing 15 people and wounding at least one, Khan said.

The 14 tankers damaged in the bombing were parked at Torkham, a town along the Pakistan-Afghan border. Torkham has witnessed many attacks on the US-NATO supply line.

U.S. and NATO commanders insist that the attacks in Pakistan barely affect their operations. But in recent years, the militaries have tried to reduce their dependence on Pakistan routes, increasingly using roads running through Central Asian countries and relying on supplies to be flown in.

Also Saturday, newly published U.S. diplomatic cables gave more details about U.S. special forces' involvement in Pakistan's military offensives against insurgents, underscoring that it went well-beyond the training of Pakistani troops that had been acknowledged publicly.

The cables were obtained through the Wikileaks organization and published by Dawn, a respected English-language newspaper in Pakistan. Several of the cables were written by Anne Patterson, then the U.S. ambassador to Pakistan.

Their release comes as Pakistan and U.S. relations are at a low point over the unilateral May 2 American raid that killed Osama bin Laden in the northwest Pakistani garrison city of Abbottabad. Pakistan is angry that it was not warned in advance of the raid and says it did not know bin Laden was hiding in the area.

Officials have since said the U.S. presence in Pakistan has been scaled back, and joint operations suspended. Some of the chill in the cooperation dates back to January, when an American CIA contractor shot dead two Pakistanis he said were trying to rob him. The incident angered the Pakistani army, but the American was freed after his victims' relatives accepted compensation.

The cables indicated that U.S. troops joined Pakistani forces for the purposes of intelligence, reconnaissance support and surveillance during 2009, a year when Pakistan was involved in multiple offensives in its northwest, pockets of which were under the control of various Taliban factions.

The U.S. cables referred to some of the sites where the cooperation was occurring as ``fusion centers.'' In April 2009, for instance, there was U.S. involvement in intelligence gathering for the Pakistani military operation in Lower Dir, which preceded a major offensive in the Swat Valley.

The U.S. appeared keen on increasing its involvement to include assistance on the ground in battle zones.

The cables obtained by Dawn involved apparent references to at least one case in which U.S. troops did provide assistance in a conflict zone, that of the Pakistani operation in Bajur tribal region in fall 2009.

That instance has previously been referenced in media reports about earlier released cables through Wikileaks. Those reports also described small U.S. troop deployments in South Waziristan and North Waziristan, where the Americans offered intelligence, surveillance and other assistance, including coordinating U.S. missile strikes.