SANAA, Yemen — Yemen’s southern separatists on Sunday broke a peace deal with the country’s internationally recognized government and claimed sole control of the regional capital of Aden, threatening to resume fighting between the two ostensible allies.

In a statement, the separatists’ Southern Transitional Council, which is backed by the United Arab Emirates, declared a state of emergency and said it would “self-govern” the key southern port city and other southern provinces. The separatists accused Yemen’s government, which is supported by Saudi Arabia, of corruption and mismanagement.

The government dismissed the separatists’ move. Foreign Minister Mohammed Abdullah al-Hadrami called for Saudi Arabia to have a “clear position” and take “decisive measures against the continuing rebellion of the so-called Transitional Council.”

The division between the two supposed allies is another facet of the country’s complicated civil war. On one side are the separatists and on the other are forces loyal to former President Abed Rabbo Mansour Hadi. Both have fought together in the Saudi-led coalition’s war against Yemen’s Shiite Houthi rebels.

The Houthis in 2014 overran major parts of northern Yemen, including the capital, Sanaa, pushing out the internationally recognized government and ushering in a war that has killed tens of thousands of people. Hadi fled first to Aden and then to Saudi Arabia.

The Saudi-led coalition intervened in the conflict in 2015 and has since waged war against the Houthis in an effort to restore Hadi’s government to power. The fighting in the Arab world’s poorest country has also left millions suffering from food and medical care shortages and pushed the country to the brink of famine.

In August, heavy fighting broke out between Hadi’s forces and the southern separatists when the latter took Aden, the temporary seat of Hadi’s government, and key southern provinces. The fighting stopped when the two groups reached a deal in November.

The deal however has yet to be implemented with both sides traded accusations on halting its implementation.

Saturday’s move came amid protests in Aden against Hadi’s government and the separatists following devastating torrential rains and floods earlier this week. The rains plunged swaths of the country under water, causing extensive damage to homes and leaving dozens of people missing, homeless or dead. It forced Hadi’s government to declare a state of emergency in Aden, which was hit hard.

Sunday’s announcement by the separatists raises concerns that Yemen could slide further into chaos amid the worldwide coronavirus pandemic. Yemen so far has only one confirmed case, in the southern province of Hadramawt, but experts and health workers have warned that the disease could wreak havoc there due to the dilapidated health system and damaged infrastructure.