A series of violent clashes between Afghan security forces and Taliban militants have claimed the lives of 11 policemen and 77 militants in the country ' s troubled west.Local Afghan security officials said the violent clashes took place in Gulistan district in Farah province, located 695 kilometers west of the Afghan capital, Kabul. "The Public Protection Police Force (PPPF) was escorting a convoy traveling from western Herat province to southern Helmand province. On Sunday evening, several hundred militants launched an attack on the convoy. The clash lasted until Monday morning. The gunfight killed 72 militants and 11 PPPF police cops," Xinhua quoted a senior police official as saying. Despite the Afghan government's operations against Taliban militants and associated groups, they have still been able to spread their influence in various regions of the war-torn country. There has been no letup in the Taliban attacks on US-led foreign troops across Afghanistan. US-led troops and Afghan forces hence are falling prey to Taliban attacks on an almost daily basis. In late April, the Taliban announced the start of their annual "offensive" against US-led and Afghan forces, vowing a new wave of attacks across Afghanistan. The militant group said it would use "every possible tactic" to inflict casualties on Afghan and US-led forces. They specifically mentioned insider and bomb attacks. The announcement prompted Afghan authorities to beef up security in major cities across the country, including the capital city of Kabul. The United States and its allies invaded Afghanistan in 2001 as part of Washington’s so-called war on terror. The offensive removed the Taliban from power, but the country is still gripped by insecurity.