SANAA, Yemen (AP) — Fierce fighting in southern Yemen between Emirati-backed separatists and the country’s internationally recognized government killed nearly 50 fighters this week on both sides, security officials said Tuesday.

The flare-up of clashes in the province of Abyan was the latest blow to a cease-fire agreement brokered by Saudi Arabia late in 2019 with the goal of closing the rift between the two sides. The sides are allies in a U.S.-backed, Saudi-led coalition fighting against the Iranian-backed Houthi rebels since 2015.

At least 47 fighters were killed and around 90 others were wounded in the clashes centered in Zinjibar, the Abyan provincial capital, and the officials described it as the fiercest in the recent months.

The officials spoke on condition of anonymity because they weren’t authorized to brief the media.

The fighting between Yemen’s internationally recognized government and the separatists’ Southern Transitional Council started in August 2019. Last fall, the two sides signed a power-sharing deal in the Saudi capital of Riyadh, but the agreement was never implemented.

The secessionist council, an umbrella group of militias backed by the United Arab Emirates, hopes to restore an independent southern Yemen, which existed from 1967 until unification in 1990.

The clashes had reopened a new front inside the larger civil war, complicating international efforts to broker a broader peace agreement to end Yemen’s conflict.

The war in the Arab world’s poorest country erupted in 2014, when the Houthis seized the capital and much of the country’s north. A Saudi-led coalition, determined to restore President Abed Rabu Mansour Hadi’s government, launched a military intervention months later.

The fighting in Yemen has spawned the world’s worst humanitarian crisis, leaving millions suffering from food and medical shortages. It has killed over 112,000 people, including fighters and civilians.