SANAA // Mortar rounds fired by Yemen’s Houthi rebels killed six civilians in the central city of Taiz on Thursday, security and medical officials said.

It came as rebel fighters retreating from the south arrived in Taiz to join the battle for the country’s third largest city.

After retaking the southern city of Aden from the Houthis last month, pro-government forces – backed by a Saudi-led coalition that includes the UAE – are advancing north.

Months of heavy fighting that has left 80 per cent of Yemen’s population in need of help to meet their basic needs – food, water, health care and shelter – according to the United Nations’ development programme.

Adding to Yemenis’ troubles, US-based charity Mercy Corps said on Wednesday that rubbish piling up on the streets of Yemeni towns is helping the spread of dengue fever and malaria.

Rubbish lying in the streets has contaminated soil and water and attracted infectious pests, said the charity, which is employing local young people to remove the waste and dispose of it safely. Mosquitoes carrying dengue fever and malaria breed and lay eggs in puddles.

At least 8,000 people in the port city of Aden have contracted dengue fever since the present crisis began five months ago, while cases of typhoid have been recorded and there are reports of malaria.

On Thursday, the UAE Ministry of International Cooperation and Development (MICAD) said in a report that the country’s humanitarian assistance to Yemen over the past four months now stood at Dh744 million, according to state news agency Wam.

Twenty-three thousand tonnes of food had been distributed to more than 1.1m people, while an additional 6,000 tonnes of food was due to arrive in Yemen shortly, the report said.

The UAE has been the biggest aid donor to Yemen so far this year, according to the UN-managed Financial Tracking Service, with UAE aid representing 31 per cent of the total aid provided by countries around the world.

The Saudi-led coalition began bombing Houthi targets in late March after the rebels – who last September captured the capital Sanaa – entered Aden. Yemeni president Abdrabu Mansur Hadi had fled to the port city after escaping Houthi house arrest in Sanaa but following the rebels’ advance on Aden he was forced to flee to Saudi Arabia where he remains in exile.

Since then, more than 4,300 people have been killed and over 22,000 wounded, the World Health Organization says.

“At some moments, I felt that the conflict in Yemen is much more of a war against civilians than a war against armed groups,” Teresa Sancristóval, head of emergencies in Yemen for medical charity Doctors Without Borders, said on Tuesday.

The price of water has doubled in the last month, forcing many families to spend one-third of their income on water, she said, adding that Sanaa is predicted to be the first capital in the world with no access to clean water.

The city of Aden in particular has seen heavy fighting, along with temperatures as high as 50ºC. Many health facilities have been closed, said Jonathan Bartolozzi, a Mercy Corps spokesman.

“There were stories of people literally having to find their way to get a drip and get home-based treatment from anyone they might know who might have had any kind of nursing training,” he said.

Peter Maurer, president of the International Committee of the Red Cross, said on Tuesday that Yemen was “crumbling.”

“Every family in Yemen has been affected by this conflict,” he said after a three-day visit to the country.

* Reuters, Associated Press