Gunmen in southwestern Pakistan attacked two trucks carrying supplies to NATO troops in Afghanistan and set them on fire on Sunday, officials said.
The incident took place near the town of Mangocher, 120 kilometres (75 miles) south of Quetta, the capital of the restive oil and gas-rich Baluchistan province, which borders Iran and Afghanistan.
"Unknown gunmen on motorcycles intercepted two trucks carrying supplies for NATO troops in Afghanistan and set them on fire," tribal police official Munir Ahmed told AFP.
"Before setting ablaze the trucks, the attackers asked the drivers and helpers to abandon their vehicles," Ahmed said.
Muhammad Ashraf, another security official in the area, confirmed the attack.
NATO trucks and oil tankers are regularly targets of arson attacks blamed on insurgents attempting to disrupt two key supply lines that cross western Pakistan bound for foreign troops fighting in neighbouring Afghanistan.
Most supplies and equipment required by coalition troops in Afghanistan are shipped through Pakistan, although US troops increasingly use alternative routes through central Asia.
Baluchistan is torn by Islamist militancy, sectarian violence between majority Sunnis and minority Shiite Muslims, and a separatist insurgency by rebels seeking political autonomy and a greater share of profits from natural resources.