Jordan's state security court has convicted five Syrians of helping Islamic State militants carry out a 2016 car bomb attack that led to the closure of the Syrian-Jordanian border.

The court on Monday imposed the death penalty on one defendant and sentenced three to life in prison. A fifth was sentenced to two years in prison.

The cross-border attack, launched from near the Rukban border camp for displaced Syrians, killed seven Jordanian border guards. In response, Jordan sealed the border.

Judge Mohammed Afif says the defendants collected information about Jordan's military positions on the border for IS. He says four admitted receiving monthly payments from IS.

The judge says the defendant who was sentenced to death had filmed the attack on his mobile phone and given the footage to IS.