The UN refugee agency announced on Thursday that fighting has forced more than 94,000 to flee their homes in war-torn Yemen since January, a grim statistic reflecting the devastation brought on by the civil war in the Arab world’s most impoverished country.

The report came as fierce clashes erupted in Yemen’s southern province on Thursday between Saudi-backed government forces and STC, leaving over 85 fighters dead on both sides, according to security officials, and displacing dozens more families.

The fighting, just east of the capital of Abyan province, Zinjibar, marks a significant escalation between the government forces and their Saudi backers, and STC — nominal allies in the five years of war against the Iran-backed Houthi rebels who control the country’s north.

Tensions between the factions peaked in late April, when the secessionist Southern Transitional Council seized the key southern port city of Aden and declared self-rule over several southern provinces, reopening a dangerous new front in the conflict. After the separatists attacked the city of Aden last August, the UAE withdrew most of its forces from southern Yemen, revealing its disillusionment with the Saudi-led campaign that has devastated the country.

Still, the separatists have more recently stepped up attacks. They launched a major assault on government troops early Thursday in Abyan, the governorate that lies between the rival forces.

Residents of Zinjibar reported hearing bursts of artillery fire and explosions as night fell. Government officials said their forces managed to thwart the attack and inflict heavy losses, destroying three tanks and five armored vehicles, as well as capturing 13 separatist fighters. Medical officials said the wounded were rushed to several hospitals in Aden, some 48 kilometers (30 miles) southwest of Zinjibar.

The officials all spoke on condition of anonymity because they were not authorized to talk to the media.

Abdul-Lateef al-Sayed, the separatist forces commander in the Abyan governorate, said his fighters were aiming to recapture the coastal town of Shoqra from government forces.

The open warfare between the factions threatens to further divide southern Yemen, where health officials from the rival sides are struggling to cope with a devastating outbreak of COVID-19. The feud has created confusion and hobbled the authorities' response, all while hospitals have shut down, medical personnel fled and bodies piled up.

Yemen’s internationally recognized government has recorded 560 coronavirus cases, including 129 deaths, but experts say that’s a result of little testing. Richard Brennan, the World Health Organization regional emergency director, said earlier that he believes the COVID-19 deaths are in the hundreds and that the number of cases are in the thousands, based on what he has heard from numerous health sources and medical providers in Yemen.

Thursday's events further exacerbate civilian suffering in the war-ravaged country, where the U.N. refugee agency said Thursday that fighting has forced 94,000 people to flee this year.

“The ongoing conflict in Yemen continues to displace people from their homes as they struggle to survive,” UNHCR said in a tweet. Only about 5,200 of the 94,000 displaced since January were able to return to their places of origin in that period, the agency added.

The civil war erupted in 2015, when the U.S.-backed, Saudi-led coalition launched an offensive against the Houthis who had overrun the capital of Sanaa and most of the country's north, forcing the internationally recognized government to seek refuge in the south.

The conflict has killed more than 100,000 people, displaced millions and set off what the U.N. described as the world's worst humanitarian disaster long before the coronavirus pandemic hit. Many families, especially among the millions displaced, can barely afford one meal a day.

Meanwhile, funding for humanitarian aid is drying up. The U.N. warned last week that a funding shortfall may force it to cut or curtail its programs to fight the coronavirus and stave off starvation for hundreds of thousands of children by the end of the month.