Ten French soldiers were killed and 21 wounded in two days of fierce fighting outside of Kabul in the single biggest loss for international forces here in more than three years, officials announced Tuesday. French President Nicolas Sarkozy announced soon after the news became public that he would immediately fly to Kabul. The Afghan officials said the battle was in the Surobi district of Kabul province, about 50 kilometers east of the capital of Kabul. Qazi Suliman, the district chief in Surobi, said a patrol of French soldiers came under Taliban attack on Monday, sparking a three-hour gunbattle. The deaths of 10 soldiers would be the deadliest attack against international troops since June 2005, when 16 American troops were killed in Kunar province when their helicopter was shot down by a rocket-propelled grenade.