Rebels and soldiers clashed in a rugged mountain region near where leftist guerrillas are holding three kidnapped Americans. Eleven soldiers and an equal number of rebels were killed.

The fighting with the Revolutionary Armed Forces of Colombia, or FARC, occurred Sunday near El Calvario, 55 miles southeast of the capital, Bogota, the army said in a communique. Ten other soldiers were injured.The site is near where the FARC is believed to be holding three American bird-watchers and an Italian businessman they kidnapped at a roadblock on March 23.

The army did not mention the kidnapped Americans - Peter Shen of New York City; Louise Augustine, a 62-year-old former nun from Chillicothe, Ill.; and Todd Mark, a 32-year-old Continental Airlines flight attendant from Houston - but did say it was engaged in combat with the same rebel batallion holding the foreigners.

A fourth bird-watcher, Thomas Fiore, was found in the jungle by a camera crew on April 2 and returned to his native New York.