A car bomb exploded on the Syrian-Jordanian border early on Tuesday, the Jordanian military said, killing six and wounding 14 Jordanian border guards in an attack.
The military said the blast went off at about 5:30 a.m., close to a makeshift tent encampment where tens of thousands of Syrian refugees are stranded, awaiting entry to Jordan.
The camp, known as Ruqban, is one of two that have sprung up along an earthen barrier, or berm, which runs along the border in a remote desert area.
No militant group immediately claimed responsibility for the attack.
The terrorist group Daesh controls large areas in neighboring Syria and Iraq, and Jordan has fortified border defenses to prevent attacks and infiltration attempts.
Jordan has also widened a crackdown on Daesh sympathizers at home, jailing hundreds in the past two years for promoting the group's ideas on social media.
The kingdom is a member of the U.S.-led international military coalition against Daesh.