KABUL/ROME (Reuters) - Four Italian soldiers were killed and one seriously wounded in an insurgent attack in western Afghanistan on Saturday, Italys Foreign Ministry said, the latest foreign casualties in a war now in its 10th year. Violence is at its worst in Afghanistan since the Taliban were overthrown by US-backed forces in late 2001. More than 2,000 foreign troops have died since the start of the war, more than half of those in the last two years. This assault against Italian soldiers is an example of the high human cost we have to pay for a mission that is fundamental for our national security, Italys Foreign Minister Franco Frattini said in a statement. The soldiers from the NATO-led International Security Assistance Force (ISAF) were returning from a mission when their vehicle was ambushed by insurgents in Farah province, a spokesman for the defence ministry told Italian television. The deaths raise Italys toll in Afghanistan to 34 since 2004. Rising casualties have in the past prompted calls from Italy to pull out. Italy has more than 3,000 soldiers in Afghanistan, mainly deployed in the western part of the country that is usually less violent than other areas in the south and the east. Foreign troop casualties have spiked this year, with more than 570 troops being killed, compared to 521 for all of 2009. June was the bloodiest month, with more than 100 killed. More than 20 soldiers have died this month alone.