The humanitarian situation in Yemen is deteriorating, relief officials say, amid continued clashes and air raids targeting Houthi fighters.
Weapons depots used by the Houthis in the capital Sanaa were among the targets hit on Tuesday, as well as the home of a senior leader of the group, sources told Al Jazeera.
In the southern city of Aden and the central city of Taiz, forces loyal to exiled President Abd-Rabbu Mansour Hadi were engaged in heavy street battles to gain control of strategic positions.
A week ago, the coalition said it was ending its nearly five-week-old bombing campaign except in places where the Houthis were advancing, to allow access for food and medicine.
But hopes for a pause in fighting has since faded and vital aid is reportedly being held up by both sides in the Arabian Peninsula nation.
Convoys of lorries
Houthis were stopping convoys of lorries reaching Aden and an arms blockade by coalition navies searching ships for weapons was holding up food deliveries by sea, Reuters news agency reported.
"It was difficult enough before, but now there are just no words for how bad it's gotten," Marie Claire Feghali, International Committee of the Red Cross (ICRC), spokesperson.
"It's a catastrophe, a humanitarian catastrophe."
Izzedine al-Asbahi, Yemeni human rights minister, echoed her remarks.
"The war and its results have turned Yemen back 100 years, due to the destruction of infrastructure ... especially in the provinces of Aden, Dhalea and Taiz," he said in the Saudi capital Riyadh.
Telecommunications within Yemen and with the outside world could be cut within days due to a shortage of fuel, state-run news agency Saba quoted the director of telecommunications as saying.
Fuel shortages were also preventing traders from moving food to market, the UN's World Food Programme said.
Fuel prices were as much as $10 per litre, and there was only enough to keep hospitals running for one more week and to prolong life-saving humanitarian operations for two weeks, the UN humanitarian agency OCHA said.
A commercial oil tanker has been waiting outside Yemeni waters since April 21 for clearance to dock, the UN said.
Hadi fled to neighbouring Saudi Arabia when the Houthis closed in on Aden last month and the port city has seen fierce fighting ever since.
An Arab coalition launched air strikes in late March to stop the advance by Houthi fighters who have taken over large parts of Yemen and effectively seized power in Sanaa.
Source: Al Jazeera and agencies