Helmand province Afghanistan.<br/> <br />It has been the site of some of the fieriest fighting in the war in Afghanistan.<br/> <br />Now the enemy is is not always on the battlefield.<br/> <br />On Thursday night an Afghan police commander and several of his men killed three U.S. soldiers in Helmand, turning guns on them after inviting them to dinner to discuss security.<br/> <br />Not including Thursday's attack, there have already been 24 incidents this year of so-called green on blue shootings, in which Afghan police or soldiers turn their guns on their Western colleagues. That compares with 21 in the whole of 2011.<br/> <br />NATO Brigadier General Gunter Katz, says often these attacks are more personal than political.<br/> <br />(SOUNDBITE) (English) NATO BRIGADIER GENERAL GUNTER KATZ, SAYING:<br/> <br />"Actually there is a kind of common denominator and that is that most of those incidents were caused by personal grievances and or stress situations."<br/> <br />More than 3,100 foreign solders have died in Afghanistan since the war was launched in 2001.
