Pakistan and Afghanistan have reopened a key trade crossing on Tuesday, officials on both sides said, after a row over travel papers as Islamabad cracks down on cross-border movements. Some Afghans seeking medical treatment in Pakistan were allowed to cross while others continued to wait at the border for permission. Ties between the two countries have increasingly frayed in recent months, with Islamabad accusing the Taliban government of failing to root out militants staging attacks in Pakistan from their soil. Kabul has always rejected the allegations. IMAGES