There have been heavy clashes between Yemen’s Houthi rebels and pro-government forces in the city of Aden.
Eyewitnesses have reported dozens have been killed in the fighting.
Fighting in the southern city has intensified as rebels and forces loyal to President Abd-Rabbu Mansour Hadi battle for control.
The rebel advance comes despite 11 days of airstrikes by a Saudi -led coalition of mainly Gulf forces.
Red Cross to deliver aid
Meanwhile a spokesperson for the military coalition said the International Red Cross is to be allowed in to deliver aid into the country.
The agency has been negotiating for nearly a week to deliver life-saving supplies.
Sunni Muslim Saudi-Arabia launched the airstrikes on March 26 targeting convoys and weapons stores in a bid to turn back the Shi’ite Houthi rebels, who already control Yemen’s capital Sanaa.
Foreign nationals evacuated
While the fighting has trapped many residents in their homes it has so far failed to inflict any decisive defeat on the rebels.
The UN says 500 have been killed over the past two weeks.
The growing death toll and humanitarian suffering has caused several countries including France, Turkey and Pakistan to begin evacuating their nationals.
On Sunday, a Pakistani aircraft rescued 170 people from Sanaa. More than 800 Pakistani citizens have already left the country.