Leftist rebels attacked an army post with mortars and catapult-launched dynamite, killing at least 15 soldiers in what appeared one of the most successful guerrilla operations in recent months.

Eleven guerrillas were killed and 11 soldiers were wounded in the attack Thursday in eastern Morazan province, according to a communique issued by the Armed Forces Press Office.The raid on the army post began an hour after guerrillas lifted a road traffic ban that had paralyzed most transportation nationwide since Monday. In lifting the ban, the rebels called on supporters to step up sabotage of vehicles that had ignored the measure.