The United Nations’ World Food Programme has temporarily suspended assistance in some parts of Sudan’s Al-Jazirah state, where it was supporting more than 800,000 people, as fighting spreads.

About 300,000 people have fled Al-Jazirah since Dec. 15, when clashes erupted, the WFP said in an emailed statement.

“Ongoing fighting makes it extremely challenging for humanitarian agencies to safely deliver assistance, especially with more and more people on the move, fleeing for their lives,” it said.

The decision was taken after clashes and air-strikes engulfed locations around Wad Madani city over the course of the past week, with the US urging the Rapid Support Forces militia that’s battling Sudan’s army to halt its attack.

The army has now withdrawn from the city and launched an investigation into why the RSF was allowed to take the territory following the removal of troops. The UN on Thursday said people displaced from Wad Madani have fled to the Gedaref, Sennar and White Nile states.

The eruption of a new front in central Sudan also threatens to derail fragile international efforts to broker a new cease-fire in the conflict that’s killed more than 12,000 people and forced 6.7 million from their homes.

The International Committee of the Red Cross on Thursday said it had withdrawn from Wad Madani as the location was “turning into another death trap” for civilians.

In just three months, ICRC and the Sudanese Red Crescent Society have facilitated almost 9,500 phone calls for people who lost contact with their loved ones.

The US has accused both sides of committing war crimes in the conflict that has devolved into proxy war with Egypt and Iran holding close ties to the Sudanese Armed Forces and the United Arab Emirates backing the RSF.

The UAE denies supplying the RSF with weapons.

US Senator Jim Risch — an Idaho Republican — and fellow Democratic lawmaker Ben Cardin of Maryland this week introduced a joint bipartisan resolution calling for a high-level special envoy to work toward ending the conflict in Sudan. “Despite global focus on crises in Europe and the Middle East, the dire situation in Sudan – characterized by extreme suffering, widespread destruction, and horrendous crimes – must not be overlooked,” Risch said in a statement.