ISLAMABAD: The US has started using the land route through Pakistan to pull American military equipment out of Afghanistan as it draws down its troops in the country, US and Pakistani officials said Monday.

The US moved 50 shipping containers into Pakistan over the weekend, said Marcus Spade, a spokesman for US forces in Afghanistan. The containers were the first convoys to cross into Pakistan as part of the Afghan pullout, he said.

Twenty-five containers that originated from a base in the southern Afghan district of Kandahar entered Pakistan through the border crossing at Chaman in southwestern Balochistan province on Saturday, said Ata Mohammed, a shipping official.

Another 25 containers entered Pakistan on Sunday through the other major Afghan border crossing at Torkham in the northwestern Khyber tribal area, said Mohammed Yousuf, a local political official.

Pakistan will be a key route for the US to withdraw tens of thousands of containers of equipment out of landlocked Afghanistan as it pulls most of its combat troops out by the end of 2014.

Pakistan closed the route for nearly seven months after US airstrikes killed 24 Pakistani troops at a post along the Afghan border in November 2011. Islamabad reopened the route in July 2012 after Washington apologized for the deaths.

During the closure of the Pakistan route, the US had to use a longer, more costly path that runs north out of Afghanistan through Central Asia and Russia. The US has also used that route to withdraw equipment.

It’s unclear what took the US so long to begin withdrawing equipment through the Pakistani route, which runs south out of Afghanistan to the port city of Karachi.

Supplies have been flowing into Afghanistan since the route reopened in July 2012.