ISLAMABAD, Pakistan – Jan Mohammed led me across the muddy yard packed with burned and still smoldering fuel tankers.

"If we don't have any security, how can we go up there?” he asked. “Nobody will drive and take fuel to NATO. It's impossible."

He was referring to the Khyber Pass in Pakistan's northwest, a key route for supplies heading to the war in Afghanistan.

Three charred shells of former oil tanker trucks belonged to him. "First they burned the tires," he said, and then flayed his arms around to illustrate the inferno that followed.

His drivers had been sleeping in their cabs, but ran to safety when they heard the first shots fired by about a dozen gunmen, who arrived on motorcycles during the pre-dawn attack on Monday.

Others were not so luckily. At least four died in the attack, and many more were injured. Yet few of them seemed surprised by what had happed.

Sitting ducks
"No security," said one driver, shaking his head, his arm bandaged from when he had fallen while escaping. That sentiment was echoed by several others who were victimized by the attack. One truck driver had salvaged two small mango plants from the shell of his cab, which he picked up along the route and planned to take home with him.

There were 55 tankers lined up in the group, some 20 of which were damaged in Monday’s attack. They had parked just outside Islamabad, Pakistan's capital, forced to wait – like sitting ducks, in hindsight – because of the closure of the border by the Pakistani authorities.

One driver pointed with disdain at a housing complex across the road, one of several large areas here reserved for military officers. "Maybe they came from there," he said. Apparently it’s not only the Americans who sometimes wonder where the Pakistani military stands on the ongoing conflict.

The Pakistan authorities say they don't have the manpower to secure the convoys, which are not their responsibility anyway. The Pakistan authorities say it is up to the contractors to sort out their own security.

Dangerous supply route
Pakistan is the main route for non-lethal supplies for U.S and allied forces fighting in Afghanistan. It can take days for supply vehicles to travel up from the port in Karachi, across Pakistan, and into Afghanistan. There are two main border crossing points, one to the south, in Baluchistan, and the other at the end of the Khyber Pass in Pakistan's northwest.

It is this second crossing that was closed by Pakistan late last week, in an apparent response to a border incursion by NATO helicopter gunships, which killed three Pakistani border guards. On Monday, NATO expressed regret for last week’s helicopter attack, saying the casualties were “unintended.”

Attacks on convoys are not uncommon, but it seems to have become open season since the border closure backed up hundreds of tankers and trucks. There have been at least five attacks on the supply convoys since the border was closed. The latest attack happened on Tuesday when a small bomb damaged a truck that was parked alongside about 100 other trucks waiting to cross into Afghanistan. However, the bomb failed to ignite the fuel, and there were no casualties.

The Pakistan government says the border will be open "soon," but has given no firm date. Meantime, the supply route to Afghanistan remains dangerously exposed.

It also comes at a time when drone attacks in the tribal areas are running at record levels. These are not popular among Pakistanis, though the government has been willing to turn a blind eye.

But analysts say the Pakistanis want to send a message to Washington – they can't be taken for granted and won't tolerate flagrant border violations.

Meantime, though, Jan Mohammed surveyed the charred remains of what had been a lucrative business.

"Afghanistan's at war," he said, "but our tankers are safer on that side of the border."

Related link: New York Times: 'U.S. military orders less dependence on fossile fuels'