Rows of destroyed Humvees and military trucks at the Portward Logistic Terminal in Peshawar on Sunday. (AP)

Peshawar, Dec. 7 (AP): Gunmen blasted their way into two transport terminals in Pakistan today and torched more than 160 vehicles destined for US-led troops in Afghanistan, in the biggest assault yet on a vital military supply line, officials said.

The US military said its losses in the raid near Peshawar would have “minimal” impact on anti-Taliban operations, set to expand with the arrival of thousands more American troops next year.

However, the attack will fuel concern that insurgents are trying to choke the route through the famed Khyber Pass, which carries up to 70 per cent of the supplies for western forces in landlocked Afghanistan, and drive up the cost of the war.

The owner of one of the terminals hit today denied government claims that security was boosted after a raid last month near the pass in which militants made off with one Humvee and later paraded it before journalists.

“We don’t feel safe here at all,” Kifayatullah Khan told The Associated Press next to the still-smouldering vehicles, predicting that most of his night watchmen would now quit their jobs out of fear. “It is almost impossible for us to continue with this business.”

The attack at the Portward Logistic Terminal reduced a section of the vast walled compound to a smouldering junkyard.

Khan said armed men flattened the gate before dawn with a rocket-propelled grenade, fatally shot a guard and set fire to a total of 106 vehicles, including about 70 Humvees.

Humvees are thought to cost about $100,000 each, though the price varies widely depending on armour and other equipment, meaning today’s losses may exceed $10 million.

An Associated Press reporter who visited the depot saw six rows of destroyed Humvees and military trucks packed close together, some on flatbed trailers, all of them gutted and twisted by the flames.

Khan said shipping documents showed they were destined for US forces and the western-trained Afghan National Army.

The attackers fled after a brief exchange of fire with police, who arrived about 40 minutes later, he said.

The nine other guards who were on duty but stood helplessly aside put the number of assailants at 300, Khan said, though police official Kashif Alam said there were only 30.

At the nearby Faisal depot, manager Shah Iran said 60 vehicles destined for Afghanistan as well as three Pakistani trucks were burned in a similar assault.

The attack was the latest in a series that have highlighted the vulnerability of the supply route to the spreading power of the Taliban and other Islamic militants in the border region.

The US military in Afghanistan said in a statement that an unspecified number of its containers were destroyed in today’s attack but that their loss would have “minimal effect on our operations.”

“It’s militarily insignificant,” US spokesperson Lt. Col. Rumi Nielsen-Green said. “You can’t imagine the volume of supplies that come through there and elsewhere and other ways.”

“So far there hasn’t been a significant loss or impact to our mission,” she said.

Still, Nato has been seeking an alternative route through Central Asia, which it acknowledges is more expensive.

Shahedullah Baig, a spokesperson for the interior minister in Islamabad, insisted today that extra security covered the terminals.

“They are fully protected, but in this kind of situation such incidents happen,” Baig said.

However, Khan, the depot manager, said that was untrue, and there were only a handful of lightly armed police at the targeted terminals today afternoon.