ISLAMABAD — Pakistan will reopen a key border crossing used to transport supplies to NATO troops in Afghanistan, authorities said Saturday — the 10th day of a blockade that has raised tensions with Washington and left stranded trucks vulnerable to attacks.

In a statement, the Foreign Ministry said it decided to reopen the border after assessing security and that authorities on both sides of the border were now coordinating to resume the supply traffic smoothly.

Pakistan closed the northwest crossing at Torkham on Sept. 30, the same day a NATO airstrike killed two Pakistani soldiers along the border.

The U.S. on Wednesday apologized for that strike.

Pakistan is a key supply route for fuel, military vehicles, spare parts, clothing and other non-lethal supplies for foreign troops in Afghanistan. Though a smaller crossing in the southwest has remained open, the closure of Torkham has left scores of trucks stranded.

In the latest in a steady stream of attacks, gunmen armed with a rocket attacked 29 tankers carrying NATO fuel supplied in southwestern Pakistan before dawn Saturday, setting them ablaze.