KABUL (AFP) - Three troops from the Nato-led International Security Assistance Force (Isaf) were killed by a roadside bomb in eastern Afghanistan Saturday, officials said. Isaf did not say which country the dead troops were from or give further details of the incident, in line with policy. There are around 140,000 international troops in Afghanistan fighting a Taliban-led insurgency, 100,000 of them from the United States. Three International Security Assistance Force members died following an improvised explosive device attack in eastern Afghanistan today, a spokes-man for the Natoled Isaf said. The latest incident takes to 542 the number of coalition troops killed in Afghanistan this year, according to an AFP tally based on that kept by independent website iCasua-lties.org. A total of 711 foreign troops were killed in Afghanistan last year, the highest annual total yet in the decade-long war triggered by a US-led invasion in 2001 which ousted the Taliban from power. Amid declining support for the war and fragile economies in the West, all foreign combat troops are due to withdraw from Afghanistan by the end of 2014, by which time Afghan forces and officials are set to be in control of the country. However, a substantial foreign troop mission training Afghan security forces is expected to remain beyond that time.