Updated

A defense attorney says five Syrians with alleged ties to the extremist Islamist State group have pleaded not guilty to charges they participated in a cross-border attack that killed seven Jordanian border guards last year.

The trial opened Wednesday in Jordan's state security court. If convicted, the defendants could face the death penalty.

The June 2016 attack was launched from near Rukban, a makeshift camp for tens of thousands of displaced Syrians on the border with Jordan. A car bomb drove at high speed into a Jordanian military installation, killing the troops.

Defense attorney Basheer Oqily says his clients were charged with involvement in the attack, as well as possessing explosives and weapons.

It was not clear how the defendants were brought from Syrian soil to Jordan.