The United Arab Emirates has indicated the redeployment of its last military personnel in Yemen after the Saudi airstrike on Mukalla city, which is a significant escalation of the conflict between the two Gulf countries.

The bombing was carried out by Saudi on Tuesday after it was reported that a shipment of arms from the UAE had been sent to Mukalla for the separatists in Yemen. The Riyadh government stated that the Emirati actions posed a very high risk and thus a signal of a serious divided opinion between the two countries about the future of Yemen.

The air raid took place against the backdrop of the UAE-protected rebels’ advances that were causing increasing tension, the most prominent of which is the Southern Transitional Council (STC). The STC along with its supporters issued a proclamation justifying the UAE’s military presence in Yemen while other armed groups were demanding that the withdrawal of Emirati troops be completed within a day.

UAE, on the other hand, called for “restraint and wisdom” and denied all the accusations from Saudi Arabia regarding the weapons shipment. Nevertheless, not long after that, Abu Dhabi disclosed that it would commence the withdrawal of its remaining soldiers. It is still unclear if the UAE-backed insurgents will retreat from the areas they have won.

The clash of interests could give rise to another battlefield in Yemen’s long civil war that has lasted more than a decade now, as the factions that were previously aligned against the Iran-supported Houthi rebels might just end up fighting each other. According to specialists, such rivalry might lead to further weakening of the already unstable Arab world’s poorest nation.

The incident has further complicated the relations between Saudi Arabia and the UAE, which have become more and more characterized by rivalry over economic benefits and political power, especially in the region around the Red Sea that is vital for global trade.

Some experts assert that airstrikes on Tuesday and Saudi Arabia’s threats are the most significant fight between Saudi Arabia and the UAE in recent history. The intensification resulted from the previous Saudi attacks on the STC last Friday which were interpreted as a blunt warning to stop the secessionists from expanding their territory.