ADEN - Fierce clashes raged Monday between rebels and loyalists in southern Yemen, leaving more than 100 dead in 24 hours, as the Red Cross faced delays to urgently needed aid deliveries.

Relief workers have warned of a dire situation in the impoverished Arabian Peninsula state, where a Saudi-led coalition is waging an air war on the Iran-backed Huthi rebels.

Most of the 114 deaths in the past 24 hours occurred in fighting between rebels and loyalists of President Abedrabbo Mansour Hadi in the main southern city of Aden. Seventeen civilians were among 53 people killed in Aden where fighting continued as rebels tried to seize a port in the city, which sits on an extinct volcano jutting out into the sea. At least 19 Huthis and 15 pro-Hadi militiamen were killed overnight in the town of Daleh, north of Aden, officials said. Seven more people were killed in the southern province of Abyan, where pro-Hadi fighters have laid siege to the base of a renegade army brigade loyal to ex-president Ali Abdullah Saleh, who is accused of backing the Huthis.

In nearby Lahj, coalition air strikes hit the strategic Al-Anad airbase and a nearby military camp, killing 10 rebels and forcing many others to flee, an army source and witnesses said. In Shabwa province, eight rebels were killed in an air raid as two others died in clashes with tribes, sources said.

Hadi, considered by the UN to be Yemen’s legitimate leader, took refuge in Aden in February after the Huthis, who hail from the mountainous north, seized power in Sanaa. Hadi fled to Saudi Arabia last month as rebels advanced on his southern stronghold, prompting the military campaign by the Saudi-led coalition, now in its 12th day. Yemen, strategically located near key shipping routes and bordering oil-rich Saudi Arabia, is sinking deeper into a multi-sided civil conflict.

The fighting has drawn in an array of armed groups including the Huthis, pro-Hadi militia, army units loyal to Saleh, southern separatists, tribes and Al-Qaeda militants. The Red Cross has appealed for an immediate truce to facilitate aid deliveries and allow people to seek water, food and medical assistance. It has been trying to fly emergency supplies into Sanaa but the plane is still stuck on the tarmac.

“We have a cargo plane with medical supplies which is ready to go,” said Sitara Jabeen, a spokeswoman for the International Committee of the Red Cross. “We have the permission for this plane but we have logistical problems for the landing. There are less and less planes landing in Yemen. We are trying to solve the logistic problems,” she told AFP. The Red Cross is also trying to deploy a team of surgeons to Aden, but says it is still awaiting authorisations from all sides in the fighting. It has called for all land, air and sea routes to be immediately opened to allow the delivery of 48 tonnes of medical supplies the organisation has ready to treat up to 3,000 wounded.

Three Indian aircraft and one Russian plane were seen landing in the capital Monday to evacuate their citizens, as Jordan said it had evacuated almost 300 nationals.

Russia has urged the UN Security Council to push for a humanitarian pause in the strikes waged by Saudi Arabia and a coalition of five Gulf monarchies, Egypt, Jordan, Morocco and Sudan.

Meanwhile, the United Nations children’s agency UNICEF said on Monday taht Yemen’s conflict is driving an already impoverished country towards humanitarian disaster, displacing tens of thousands of families and exposing many more to the threat of disease and malnutrition.

The Arabian Peninsula’s poorest state has endured years of unrest, but nearly two weeks of war between rebel Houthi fighters and pro-government forces - backed by a Saudi-led campaign of air strikes - has put millions of people in danger. UNICEF’s Yemen representative Julien Harneis said “many, many children” had been killed in the fighting. Hospitals have been shelled and schools taken over by combatants.

Fuel shortages threaten to disrupt child immunisation programmes - which need vaccines to be kept refrigerated - and government cash handouts to the poorest third of the population have been suspended.

At the same time the cost of water has risen, as generators pumping the water become more expensive to run, and prices of increasingly scarce food have gone up as people’s incomes fall. The huge displacement of people, with families fleeing the worst-hit cities, also means deteriorating hygiene and sanitation conditions and possible spread of disease. “We are rushing to a humanitarian disaster,” Harneis told Reuters.

UNICEF and the International Committee of the Red Cross are both trying to fly aid shipments into Yemen on Tuesday to start addressing the dire conditions, but say they have struggled to get approval from the Saudi-led coalition and to find planes which will fly into the conflict zone.

“Our main focus is going to be water and sanitation, and medical (aid),” Harneis said by telephone from Jordan.

UNICEF said at least 62 children were killed in the last week of March in Yemen. Harneis said the figure was likely now to be “much, much worse”.

In part that may be because of the large proportion of children fighting in the ranks of Yemen’s many armed factions.

Harneis said child recruitment was widespread. “All of those more tribal type groups ... up to a third of them are children.”