Yemen's warring parties are heading to Geneva for U.N.-sponsored talks from Sunday, but there are few if any signs that either is ready to make the compromises necessary for a deal.

The United Nations envoy to Yemen, Ismail Ould Cheikh Ahmed, has said the talks can end over two months of conflict that has killed almost 2,600 people, and save the Arabian Peninsula country from permanent division.

An air strike by the Saudi-led coalition on the old quarter of the Yemeni capital killed five people on Friday and destroyed three houses in the UNESCO-listed heritage site.

Residents said the pre-dawn strike was the first direct hit on old Sanaa since the launch of the bombing campaign against Huthi rebels in late March.

The missile hit the Qassimi neighbourhood, which boasts thousands of houses built before the 11th century, an AFP journalist reported.

It did not explode but it still destroyed three three-storey houses and killed five residents, including a woman and a child, medics and witnesses said.

The target of the raid was not immediately clear amid conflicting statements from residents about whether rebels had occupied one of the houses hit.

The old city has already suffered some damage from air strikes on nearby targets, including the defence ministry, prompting a protest from UNESCO in May.

DUBAI—Eighty percent of Yemen's population, or more than 20 million people, need some form of humanitarian assistance as Arab air strikes and civil war ravage the impoverished country, aid agency UNICEF said on Thursday.

The figure is up by almost 5 million people since the organization's latest report last week.

For over 11 weeks, an Arab military coalition has been bombing the Houthi militia, the dominant group in Yemen at the moment, in a bid to restore the country's exiled president to power and support local fighters resisting the Houthi advance in battlefields nationwide.