Pakistan-Afghanistan border: Main crossing closed after exchange of fire

Hundreds of trucks are stranded at the main border crossing between Pakistan and Afghanistan after gun battles between security forces on Wednesday.
Trucks are backed up for kilometres on both sides of the border waiting to cross.
The security situation remains tense.
Pakistani government and military officials say they are in contact with Afghan authorities to try and defuse tensions.

Al Jazeera’s Kamal Hyder is at the Torkham border crossing for us for the latest updates.