Pakistani authorities said on Friday that up to 50 Islamist militants and four troops had died in clashes in an area where a US report this week criticized the military’s efforts to beat insurgents. The deaths, which couldn’t be independently verified, were reported in the Mohmand area, part of Pakistani restive tribal belt along the border with Afghanistan. According to local officials, militants ambushed a security convoy near Baizai in Mohmand on Thursday, sparking an exchange of fire. Four troops and 10 insurgents were killed in that attack. Around 40 fighters were killed in a separate incident when military jets targeted their hideouts in different parts of Mohmand.