Jordan's army said on Sunday its border guards killed five people who were approaching its frontier from Tanf, a Syrian desert town where U.S. special forces training rebels are based.
The town has been a flashpoint in recent weeks as militias backed by Iran have tried to get near the U.S. garrison, prompting U.S. coalition jets to strike back.
Tanf lies near the strategic Damascus-Baghdad highway that was once a major weapons supply route for Iranian weapons into Syria.
The Jordanian army said it destroyed a car and two motorbikes in the incident.
The army statement did not give any details of the identity of the men and whether they were smugglers or militants in the area where Jordan's northeastern borders meet both Iraq and Syria.
The statement however said that before the shooting, a convoy of nine cars had approached from the Tanf area but fled after the army fired warning shots.
Islamic State militants launched a suicide attack last April on the heavily defended base in which the Pentagon said an estimated 20-30 IS fighters were involved. U.S. jets bombed the militants in the hit and run attack.
Staunch U.S. ally Jordan has also been threatened by the militants.