Fresh aid reaches Yemen capital

The Red Cross has delivered its second plane-load of aid to Yemen's capital in as many days as hundreds wounded in fighting between pro-government forces and Iran-backed rebels wait for treatment.

Fierce clashes in south Yemen killed at least 25 people over Friday night, before a fresh wave of pre-dawn air strikes by a Saudi-led coalition against positions of the Huthi Shi'ite rebels in Aden, the region's main city.

The International Committee of the Red Cross says its plane was carrying medical equipment required to treat the wounded after weeks of intense fighting across the country.

ICRC spokeswoman Marie Claire Feghali said the cargo of 35.6 tonnes included 32 tonnes of medical aid, with the rest water purifying equipment, electric power generators and tents.

The ICRC and UN each sent planes to Sanaa on Friday carrying 16 tonnes of medicine and equipment.

They were the first aid supplies to reach the capital since the Saudi-led coalition launched air strikes against the rebels late last month.

More than two weeks of heavy bombardment against opponents of exiled Yemeni President Abedrabbo Mansour Hadi and fighting between rival militias has prompted the UN to call for a freeze in the violence.

UN humanitarian coordinator in Yemen, Johannes Van Der Klaauw, told reporters in Geneva that an "immediate humanitarian pause in this conflict" was desperately needed.

He insisted that the aid delivered to date was far from sufficient.

"The situation in Aden is extremely, extremely preoccupying if not catastrophic," he said, warning that Yemen's second largest city had fallen prey to "urban warfare" and "uncontrollable militias".

The World Health Organization says nearly 650 people have been killed and more than 2000 injured in the recent escalation in violence.

Street fighting in Aden between the Huthis and Hadi loyalists cost the lives of at least seven combatants in a 12-hour period overnight Friday, said a health official in the city.

Among them were "an elderly woman, a man and a child killed by snipers" from the rebel forces, the official said.