At least six Jordanian soldiers have been killed and 14 hurt in a car bomb attack near a makeshift refugee camp on the Syria-Jordan border, officials say.
Jordan's military said several other "hostile" vehicles were destroyed.
More than 50,000 refugees are stranded at Rukban, awaiting entry. Jordan currently only allows in about 50 to 100 each day, citing security concerns.
Many of them are believed to have fled areas controlled by the jihadist group Islamic State (IS) in Homs province and neighbouring Raqqa, where forces loyal to President Bashar al-Assad have made gains in recent months with the support of Russian air strikes.