Up to 20 suspected Taliban militants were killed Sunday in a clash with a U.S. patrol in southern Afghanistan, the U.S. military said. "An unprovoked attack on a coalition patrol today left 15 to 20 militants dead," a statement said. U.S. aircraft and attack helicopters engaged the enemy after the patrol came under small-arms fire northwest of Gereshk, in the province of Helmand, dpa reported. "No coalition personnel were injured in the incident," the statement added. Some 20,000 U.S.-led troops remain in Afghanistan hunting remnants of the ousted Taliban regime and their allies from the al-Qaeda network, mainly in the south and southeastern regions of the country, dpa reported. In recent months, the insurgents have accelerated their military attacks U.S. and Afghan troops, mainly in south and southeastern region of the country. --SP 2223 Local Time 1923 GMT