Dec 30 - Saudi Arabia said on Tuesday its national security was a red line and backed a call for UAE forces to leave Yemen within 24 hours, shortly after a Saudi-led coalition carried out an airstrike on the southern Yemeni port of Mukalla.

The warning represented Riyadh's strongest language against Abu Dhabi yet, as the coalition struck what it described as foreign military support to UAE-backed southern separatists, and the head of Yemen's Saudi-backed presidential council set the deadline for Emirati forces to leave.