MINGORA, Pakistan (Reuters) -- A suicide car-bomber has killed eight people in an attack aimed at a military checkpost in northwest Pakistan's Swat Valley, military officials said.
Al-Qaeda and Taliban militants have stepped up attacks on security forces, especially in the northwest where Pakistan is trying to eliminate militant strongholds from where they orchestrate violence in Pakistan and Afghanistan.
"The attacker was riding in a car packed with explosives. He blew up the car a few hundreds meters before the checkpost," said one of the military officials in the valley, who declined to be identified.
Seven civilians who happened to be passing by at the time were killed, as well as one soldier, the official said.
Earlier, two drivers of trucks transporting supplies to Western forces in Afghanistan were killed in a grenade and gun attack near the Pakistani city of Peshawar, a transport company official said.
The trucks were parked at a terminal on the outskirts of Peshawar when militants fired rocket-propelled grenades at them, setting some of them on fire, police said.
"When the fire was raging, the attackers started firing and two drivers were killed," Mohammad Haroon, an official of Al-Faisal Cargo, a private company involved in trucking supplies to Afghanistan, told Reuters.
Militants in Pakistan have stepped up attacks on supplies going through northwest Pakistan's Khyber Pass, a vital supply link for Western forces in landlocked Afghanistan.
The U.S. military sends 75 percent of supplies for the Afghan war through or over Pakistan, including 40 percent of the fuel for its troops, the U.S. Defense Department says.
There are only two major routes into Afghanistan from the Pakistani port of Karachi, one through the Khyber Pass and the other through the town of Chaman to the southwest, the gateway to the southern Afghan city of Kandahar.
Pakistani authorities halted movement of supplies through the Khyber Pass for a week in November after militants hijacked 13 trucks carrying Western force supplies.