El Salvador troops to support rescue mission to find four UN-backed soldiers who disappeared after ambush. Around 1,000 soldiers from El Salvador have been sent to Haiti after four Salvadoran members of a UN-backed force went missing during a gang ambush on the. El Salvador has sent about 1,000 troops to Haiti after four Salvadoran members of a UN-backed security mission went missing in a gang ambush on the outskirts of.