The so-called Islamic State (IS) group has said it carried out a suicide truck-bomb attack that killed six Jordanian security personnel on the border with Syria, BBC News reports.

A statement said "a fighter of Islamic State" had carried out the attack near a makeshift refugee camp in the remote Rukban area last Tuesday, June 21.

IS has previously threatened to "break down" Jordan's borders.

The kingdom is part of the US-led coalition against IS. Its military jets have carried out air strikes on militants in Syria.

The attack in Rukban was the first of its kind in Jordan since the conflict in Syria began in 2011.

The suicide bomber drove an explosives-laden lorry at high speed over the border from Syria and detonated it near a Jordanian military post.

Four border guards were killed along with two personnel from the Civil Defence and Public Security Department.

In response, King Abdullah said Jordan would "respond with an iron fist" against any group that sought to harm its borders or security.

Jordan later declared its northern and north-eastern borders would become closed military zones.

Aid workers say more than 50,000 refugees are stranded at the Rukban camp, living in deplorable conditions while awaiting entry to Jordan.