Houthi rebels are committing crimes against humanity by deliberately shelling civilian areas of Taez city and preventing essential supplies from reaching its residents, the Yemen government has told the United Nations.

The rebels are systematically using heavy artillery and tank fire on homes in densely populated residential areas of Taez city, Abdrabu Mansur Hadi’s government said in a letter to UN secretary general Ban Ki-moon.

It said the targeted areas were devoid of any military activity, and expressed confidence the UN would take a stand against the Houthi violations of international humanitarian law.

The publication of the letter on Friday came as the death toll from rebel shelling in the city over the previous two days rose to 19, including four children.

“With the clashes and shelling still targeting Taez city, the residents in these areas cannot leave their houses and they depend on whatever they have at home for food,” said Fareed Al Homaid, a journalist based in the besieged city.

Mr Al Homaid said five pro-government fighters from the popular resistance had also been killed at different fronts in the city over two days.

Control of the city, the capital of Taez province, is divided between pro-government and rebels forces and months of fighting have taken a heavy toll of civilians. Many have joined the resistance after losing loved ones in rebel fire. The rebels control the roads into the city and have blocked supplies of food, water and medicines entering.

The resistance is fighting the rebels and allied renegade units of the Yemeni military on several fronts in Taez province but the fiercest clashes have been in the provincial capital.

The pro-government forces are receiving support from the Saudi-led regional coalition seeking to restore Mr Hadi’s government, including air cover, weapons and, most recently, armoured military vehicles from the UAE.

However, the resistance is struggling to make headway against the rebels, a senior leader said.

“We are fighting the Houthis, which is in fact the Yemeni army, and the fighters of the resistance are normal people who are not properly trained for combat,” he told The National, speaking on condition of anonymity.

He said the resistance could stop the Houthis from taking fresh territory and recapture parts of Taez city with coalition-supplied weapons and vehicles, but it would be difficult to liberate the whole province without help from coalition troops.

“If the coalition sends us troops, they know how to fight and how to use weapons properly and they will observe us and train us how to fight,” he said.

Yemeni officials have said that coalition troops from Sudan who arrived in Aden last month would take part in the liberation of Taez.

“We will not surrender to the Houthis. We will fight them even with our own weapons until we exile them from Taez, but if the coalition forces will help us as they did in Aden that will be great and we can liberate the province easily.”

He said the resistance would prevent the Houthis from taking over new areas and that the Southern Resistance in Aden and Lahj provinces was also sending fighters to Taez to help local forces launch a decisive battle for control of the province and its capital city.

Meanwhile president Hadi has issued instructions declaring as null and void all measures and resolutions authored by the rebels at all state civilian and military institutions, regarding civil service and including employment, retirement and appointments.

The official Yemen News Agency said Mr Hadi sent the instructions to his vice president and prime minister Khaled Bahah on Thursday night.

He stressed that relevant action should be taken urgently in coordination with the relevant authorities to render all the rebels’ measures and resolutions illegitimate. The National