REUTERS/Rodi Said The US-led coalition fighting ISIS in Syria launched its third strike in as many weeks on pro-regime forces inside a deconfliction zone around al Tanf, near a border crossing in Syria's southeast desert. Two US officials told CNN that Thursday's strike came after three vehicles were seen entering the deconfliction zone, and two the vehicles were hit when they were 24 miles from the base at al Tanf. Following that engagement, a US aircraft downed a pro-regime drone that was dropping bombs near coalition troops. "The pro-regime UAV, similar in size to a U.S.