Some Afghan troops fired two rockets at a Pakistani army base just across the Afghan border. There has been a border dispute in the area for several weeks, because the Pakistani army, for the first time, is trying to control the border. But there has never been official agreement on exactly where the border is. Previously, the local tribes put the border where they agreed it would be. But the Pakistani has a different map, and a different location for the border posts (several of which are now a few kilometers deeper into Afghanistan).  The troops and the tribesmen are shooting at each other over this.