Three NATO troops were killed Friday in Afghanistan in a surge of attacks that raised the death toll to 17 over the past three days for international troops in the country. One service member died Friday in an insurgent attack in the east and another was killed by a roadside bomb in southern Afghanistan, an alliance statement said. It did not give nationalities or exact locations of the attacks. France said a French soldier died Friday of wounds sustained in a clash in the Uzbin Valley east of Kabul the day before. On Thursday, eight NATO troops were killed in a spate of attacks, including four separate roadside bombings the weapon of choice for insurgents who rely on guerrilla tactics to counter intensified NATO-Afghan operations. It has been the deadliest year for international forces in the nine-year Afghan conflict. Troop numbers have been ramped up to turn the screws on insurgents and casualties have mounted.