Relief groups have warned that renewed war in Yemen faces the risk of a 'humanitarian catastrophe.'

Nearly one million people have stopped receiving food assistance because health infrastructure has been affected by war casualties.

Humanitarian groups, the International Committee of the Red Cross (ICRC) and the World Food Program (WFP) have sounded the alarm over the worsening humanitarian situation in Yemen amid the escalation of conflict.

According to the WFP, about 800,000 people have been spared food aid due to the rapid shifting of front lines between the Saudi-backed forces of the internationally recognized government and the Iran-aligned Houthis.

"This is the kind of situation that can quickly turn into a humanitarian disaster," said Al-Khader Dolom, WFP country director in Yemen.

The crisis is worst in Taiz, Yemen's third-largest city, where an estimated 600,000 people, including 200,000 women and children, lack access to food aid, the United Nations said in a statement.

Taiz has been the focus of recent clashes and is besieged by Houthi forces, jeopardizing the delivery of aid.

WFP said the loss of access is particularly worrying given that Taiz has some of the highest levels of food insecurity in the country.

The organization added: Across Yemen, more than 18 million people do not have enough food, while the latest monitoring shows that a record 74 percent of households in accessible areas cannot meet their daily food needs.

Meanwhile, according to a statement released by the International Committee of the Red Cross, "sunken" health facilities in Marib, Taiz and along the coast of the Red Sea took the brunt of the fighting in those areas, with some receiving more than 700 cases. In a single week,

Firas Abu Samrah, coordinator of health services for the International Committee of the Red Cross, said that only a few centers operating in Yemen can provide comprehensive care for the wounded.

He said frontline hospitals are admitting a large number of injured while facing a shortage of surgical equipment, anesthetics, oxygen and medicine.

"Additional pressure on hospitals could mean fewer beds, less equipment and less capacity to treat people with non-conflict conditions," said Eduardo Toro, an ICRC surgeon at Marib General Hospital.

Christian Cipolla, head of the ICRC delegation in Yemen, said the country's battered health system is ill-prepared to deal with any further conflict.

"Our concern is that the system may have little capacity to absorb a large wave of casualties," he said.