GENEVA, Switzerland – More than 300,000 people have fled their homes in western Yemen because of intensifying fighting between the Houthis and Saudi-backed government forces, the UN said on Sunday.

Almost all were displaced in the last two months, and they "urgently need shelter, food, clean water and health care", the International Organization for Migration (IOM) said in a statement.

Yemen slid back into war in July after four years of relative calm, amid fallout from the wider Middle East conflict.

Hostilities intensified in September, with a Houthi offensive in the west.

Saudi Arabia has carried out airstrikes against Houthi positions and the Iranian-backed group has stepped up attacks inside Saudi territory.

The IOM said it was providing medical aid to civilians in five locations.

"Without more funding, thousands of families could be left without the help they urgently need," said Abdusattor Esoev, IOM Yemen Chief of Mission, quoted in the statement.

It said fighting has sent prices for basic goods soaring and put basic food supplies out of reach of many families.

It said it needed $45 million over the next six months to continue providing "lifesaving assistance".

It urged "all parties to the conflict to protect civilians and humanitarian workers and ensure safe and unimpeded humanitarian access, particularly in hard-to-reach areas of Ta'iz", a key western town.