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 Iran-backed Huthi Shiite rebels.
At least 53 people have been killed in 24 hours of fighting between rebels and fighters loyal to President Abedrabbo Mansour Hadi in the main southern city Aden, medical and army sources said on Monday.
Seventeen civilians were said to be among the dead.
Witnesses said that clashes continued on Monday as rebels tried to seize a port in the city, which sits on an extinct volcano jutting out into the sea.
In the town of Daleh, about 120 kilometres (75 miles) north of Aden, at least 19 Huthi rebels and 15 pro-Hadi militiamen were killed in fighting overnight, local officials said.
Seven more people were killed in clashes in the southern province of Abyan, where Hadi loyalists have besieged the base of a rebel army brigade loyal to ex-president Ali Abdullah Saleh, who is accused of backing the Huthis.
Hadi, who is backed by the United Nations as Yemen’s legitimate leader, took refuge in Aden in February after the Huthis, who hail from the mountainous north, seized power in the capital Sanaa.
– Aid flight ‘problems’ –
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, Sunni 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,” Sitara Jabeen, a spokeswoman for the International Committee of the Red Cross (ICRC) in Geneva, told AFP.
“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 added.
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 and surgical kits the organisation has ready to treat the 2,000 to 3,000 people who have been wounded in the fighting.
An AFP photographer at Sanaa airport reported that three Indian aircraft and one Russian plane landed in the capital on Monday to evacuate their citizens.
Russia presented a draft resolution to the UN Security Council on Saturday calling for a humanitarian pause in the Saudi-led air war.
Riyadh has assembled a coalition of five Gulf monarchies, Egypt, Jordan, Morocco and Sudan to wage air raids on the Huthis.