Yemen’s southern separatists celebrated on Thursday after making advances in the key eastern province of Hadramout, following clashes with forces loyal to the internationally recognized government and tribal forces in the province. The fighting exposed cracks in the relationship between Saudi Arabia and the United Arab Emirates, which backs the separatists, while Riyadh supports other tribes. 

What happened: On Wednesday, the UAE-backed Southern Transitional Council announced it would conduct a military operation to “restore stability in Wadi Hadramout, end the state of lawlessness and stop the exploitation of the region by forces alien to the valley and the province.”

In a statement, the STC accused some elements of turning the Wadi Hadramout area into a hotbed for extremist organizations such as the Islamic State and al-Qaeda in the Arabian Peninsula as well as using the region for smuggling activities benefiting the Iran-backed Houthi rebel group.

According to several local reports, the STC’s military wing, the Southern Armed Forces, began mobilizing troops and armored vehicles across Hadramout earlier this week following the seizure of key oil facilities in the province by rival tribal groups aligned with Saudi Arabia.