The government said that 10 of its soldiers had died and seven others had been wounded during the past 24 hours while pushing back a new ground and artillery attack from the Houthis against army personnel at the western entrance to the city.

“This (the attack) is a flagrant challenge to all initiatives and endeavors aimed at ending the war and achieving peace, undermines efforts to extend and expand the humanitarian truce, and seeks to impose the siege on the city of Taiz, which has already been besieged for seven years,” the government said.

On Sunday night, the Houthis shelled troops manning Al-Dhabab Road before advancing on the ground to seize control of it and ultimately tighten their siege of Taiz.

Heavy fighting broke out between troops and Houthis after their attack, but by Monday morning troops had successfully repelled the offensive, military officials said. They described the attack as the fiercest and deadliest since the beginning of the UN-brokered truce on April 2.

The Houthi attack came as a UN-sponsored de-escalation military committee from the government and militia arrived in Amman to discuss violations of the truce and opening roads in Taiz.

“With this dangerous escalation, the government calls on the UN envoy to assume his responsibilities and condemn these criminal, escalatory acts of the Houthi group in Taiz,” the government said.

Under the UN truce, which has been renewed twice, the warring parties agreed to stop hostilities, allow commercial flights from Houthi-held Sanaa, allow more fuel ships to enter Hodeidah port, and engage in discussions in Amman to open roads in Taiz and other provinces.

Opening roads in Taiz is the only element of the truce that has not been implemented as the Houthis have refused proposals on lifting their siege. They suggested opening one small and unpaved road in the city.

Abdul Kareem Shaiban, head of the government’s delegation at the Taiz siege talks in Amman, told Arab News on Monday that the UN Yemen envoy Hans Grundberg had been alerted about the Houthi attack and military deaths. He said the city had been bracing itself for the attack for a long time as the Houthis were amassing fighting outside the city during the truce.

“The militia neither believes in truces, stability and international charters, nor religious or tribal norms,” Shaiban said.

Rights groups on Monday called on the Houthis to end their siege by opening roads in and around the city and allowing residents to freely leave and enter to help alleviate the worsening humanitarian crisis.

“Houthi restrictions have forced civilians to use dangerous and poorly maintained mountain roads that are the only connection between Taiz city’s besieged population and the rest of the world,” said Michael Page, deputy Middle East and North Africa director at Human Rights Watch.

“Opening the main roads would help immensely to alleviate the suffering of a population that has been in near-total isolation for seven years.”