Southern Transitional Council forces clashed on Wednesday with presidential guards in Aden, the seat of Yemen’s government, and three people were killed and nine injured, local officials and residents told Reuters.

The violence highlighted a rift within the Saudi-backed coalition battling the Iran-aligned Houthi movement in a more than four-year war that has killed tens of thousands of people and pushed Yemen to the brink of famine.

TheTransitional Council and the internationally recognized government of President Abd-Rabbu Mansour Hadi are nominally united in their battle against the Houthis.

But they have rival agendas for Yemen’s future, and a missile strike in Aden last week that killed dozens of southern soldiers raised friction between them.

Just before Wednesday’s clash, hundreds ofTransitional Council  supporters attended a funeral for some of the southern soldiers and a prominent commander near the hilltop presidential palace.

As the crowd chanted anti-government slogans, shooting was exchanged with presidential guards.

Presidential guard Brigadier General Sanad al-Rahwa told Yemeni news outlet Masdar Online that his forces had clashed with armed groups trying to storm the presidential palace and central bank.

After the funeral, the vice-president of the separatist Southern Transitional Council (STC), Hani Ali Brik, called on supporters to march on the palace and overthrow the government, but there was no sign such a march had begun.

Interior Minister Ahmed al-Mayssari said the government had so far practiced restraint to maintain stability in Aden but was “fully ready” to combat any actions targeting the state’s institutions.

“We call on the Yemeni people not to respond to such calls as they only aim for war and only serve the Houthis,” he said.