KABUL, July 14 – Insurgents killed nine US soldiers in an assault on an Afghan army and Nato outpost in north-eastern Afghanistan on Sunday, making it one of the worst days for foreign troop casualties in the country since 2001.

Afghanistan is suffering from a rising tide of violence this year, with a sharp increase in Taliban attacks, especially in the east where Nato says militants have taken advantage of peace deals in Pakistan to cross the border and fight in Afghanistan.