International aid group Medecins Sans Frontieres said on Thursday it is witnessing “a dramatic influx” of critically ill COVID-19 patients in war-stricken Yemen, as a second wave overwhelms the country's depleted medical facilities.

“We are urging all medical humanitarian organizations already present in Yemen to rapidly scale up their COVID-19 emergency response,” said Raphael Veicht, MSF head of mission in Yemen.

“All aspects of the COVID-19 intervention are lacking and need greater international support, from public health messaging, to vaccinations, to oxygen therapy—support is needed across the board,” Veicht added in a a statement.

More than 3,000 infectious cases, including 800 deaths, have been recorded in Yemen since the outbreak of the pandemic. However, the actual toll is believed to be much higher given the scarcity of testing.

The Geneva-based relief agency said that it has been running the COVID-19 treatment center in Al Gamhouria hospital in the city of Aden where all 11 ICU beds are currently occupied. Another 46 are in the inpatient department, added the statement.

“Unfortunately, many of the patients we see are already in a critical medical condition when they arrive,” said Line Lootens, MSF medical coordinator in Yemen. “Most patients need very high levels of oxygen and medical treatment. Some patients also require mechanical ventilation at the ICU, which is difficult and requires a very high level of medical care.”

The devastating conflict in the Arab world’s poorest country erupted in 2014, when Iranian-backed Houthi rebels seized Yemen’s capital, Sanaa, and much of the country’s north. That prompted a U.S.-backed Arab military coalition led by Saudi Arabia and the UAE to intervene months later in a bid to restore the government of Yemeni President Abed Rabu Mansour Hadi to power.

The conflict has killed some 130,000 people and spawned the world’s worst humanitarian disaster.