Pakistan fires heavy artillery at Afghan forces on Khyber Pass border

PESHAWAR: Pakistani troops fired heavy artillery at Afghan forces at their main Khyber Pass border crossing on Wednesday, the Pakistani military said, an escalation after days of clashes that have killed four people and stranded thousands on both sides. Relations between the U.S. allies have never been close but have been strained over the past 15 years by Afghan accusations that Pakistan supports the Taliban who are fighting to unseat the U.S.-backed government in Kabul. Pakistan denies that.