Riyadh, Dec. 30 -- Tensions between Saudi Arabia and the United Arab Emirates escalated over Yemen, warning that any threat to its national security is a "red line" and demanding the withdrawal of UAE-backed forces from Yemeni territory within 24 hours.

In a strongly worded statement, the Saudi Ministry of Foreign Affairs expressed disappointment over the "brotherly United Arab Emirates'" support for the separatist Southern Transitional Council (STC), accusing Abu Dhabi of pressuring the group to conduct military operations near Saudi Arabia's southern borders in the Yemeni governorates of Hadramout and Al-Mahara.

Saudi Arabia also released footage showing UAE ships offloading weapons and armoured vehicles that were attacked, saying the m...