ADEN, Yemen - Houthi forces fought street-by-street battles with local militia in the old centre of Aden on Wednesday, as the first boatloads of emergency medical aid reached the south Yemeni port city, which relief workers say faces a humanitarian catastrophe.
Residents saw a dozen bodies strewn on the streets and said several buildings were burnt or demolished by rocket fire. Mosques broadcast appeals for jihad against the Houthis, Iran-allied fighters who have taken over large areas of Yemen.
The Houthi attack in the central Crater neighborhood, backed by tanks and armored vehicles, was at least partially repelled, residents said, and Houthi gunmen had also been driven from some northern neighborhoods.
Iran, which denies arming the Houthis, has condemned the Saudi-led offensive. Tehran sent two warships to the Gulf of Aden on Wednesday, saying they would protect Iranian shipping.
Aden has been the target of a three-week-old assault by the Shi'ite Muslim fighters, who control the capital Sanaa. Their campaign prompted Tehran's rival Saudi Arabia and its allies to launch air strikes against the Houthis.
Saudi Arabia's leading role against the Houthis has turned Yemen into the latest theatre of a regional proxy conflict between the Gulf's leading Sunni Muslim and Shi'ite Muslim powers - a struggle also playing out in Syria, Lebanon and Iraq.
The fighting has had a devastating impact on parts of Aden. Scores of people have been killed, water and electricity have been cut off in central neighborhoods, and hospitals have struggled to cope with the casualties.
"It's nearly catastrophic," said the International Committee of the Red Cross spokeswoman in Yemen, Marie Claire Feghali.
Related Coverage › Kerry says US aware of Iran's support to Yemen's Houthis › Al Qaeda in Yemen offers bounty for Houthi leader: SITE › UAE says sees systematic Iranian meddling in Yemen, region › SLIDESHOW Yemen's Houthis battle in central Aden, first medical aid arrives
"Shops are closed, so people cannot get food, they cannot get water. There are still dead bodies in the street. Hospitals are extremely exhausted."
A boat carrying 2.5 tonnes of medicine docked in Aden on Wednesday, the medical aid group Medecins Sans Frontieres said. MSF said it was the first shipment it had delivered to the city since the fighting escalated.
The ICRC said a surgical team also arrived by boat in Aden, which has a population of one million.
The World Health Organisation says at least 643 people have been killed in the conflict and more than 2,200 wounded. Tens of thousands of families have been displaced.