Pakistani activists have blocked the main supply route to Afghanistan to protest against US drone strikes.
Opposition leader Imran Khan called for the blockade, saying it would continue until American drone attacks in the northwest were stopped.
Khan blamed drones for killing civilians and for putting a stop to any chance of peace with the Taliban. The blockade was imposed over the weekend after he was angered by a US drone strike in the Hangu district of the northwestern Khyber Pakhtunkhwa province, which is ruled by Khan's party.
The activists and workers, belonging to Khan's Pakistan Tehreek-i-Insaaf (PTI), have continued to block the key supply route, and Pakistani police said they had been harassing truck drivers and turning back vehicles carrying NATO goods on Monday.
More from GlobalPost: The Pakistani Taliban ruined my holiday
The roadblock comes almost a month after Pakistani Taliban chief Hakimullah Mehsud was killed by a drone strike on a compound in North Waziristan.
Mehsud had indicated that he might be prepared to talk, but his death came just one day before he was to meet with a team of mediators. His successor, Mullah Fazlullah, appears to have rejected any peace initiative.
The US considers drone strikes to be an effective weapon against Taliban and al-Qaeda militants, which the country says use Pakistan as a base from where it launches attacks on international troops in Afghanistan.