SANAA, Yemen (AP) — Saudi Arabia's King Salman had to step in recently to calm tensions between President Abed Rabbo Mansour Hadi and the United Arab Emirates, Yemeni officials said Wednesday.

Hadi had accused the Emiratis, who are supporting him in Yemen with troops against Shiite rebels known as Houthis, of meddling in sovereign affairs, especially in the southern city of Aden where they had allegedly encouraged some locals to reject government orders, they said.

Salman's meeting with Hadi last weekend in Riyadh had been unplanned, but came just days after Hadi fired Minister of State Hani Bin Braik and Aden Gov. Aidarous al-Zubaidi in what was the latest chapter in the stand-off between Hadi and the UAE.

Relations between the two sides have also been tense over allegations the Emiratis are offering patronage to southern Yemeni politicians campaigning for secession. Aden has been the seat of Hadi's government since 2014, when rebels seized the capital, Sanaa.

Hadi told Salman the Emiratis were attempting to create an "alternate legitimate leadership" to his Yemeni government, said the officials.

Other officials said that despite Hadi's urging to stand down, thousands of pro-secessionist protesters were heading toward Aden for a demonstration on Thursday to protest the sacking of Gov. Zubaidi. All officials spoke on condition of anonymity because they were not authorized to talk to journalists.

Yemen's war has killed more than 10,000 civilians and pushed the Arab world's poorest nation to the brink of famine.

It pits the coalition of mostly Sunni Arab countries against the Iran-backed Houthis and their allies. After the Houthis seized Sanaa and other areas in 2014, Hadi's internationally-recognized government fled to Saudi Arabia. A Saudi-led coalition began airstrikes against the rebels in March 2015, followed by smaller ground operations later.