Clashes in Yemen are reportedly continuing despite a fragile five-day truce declared by the pro-government Arab-led coalition coming into effect.
At least 10 Houthi rebels were killed after their vehicles were targeted by an explosion in Zinjibar in Abyan province minutes before the truce took hold on Sunday before midnight, sources have told Al Jazeera.
Within 90 minutes, the Houthis were reportedly shelling residential areas in the country's third largest city of Taiz and were regrouping to take control of the city, our sources said.
The Houthi rebels earlier on Sunday said they had not committed to the humanitarian pause declared by the coalition. They have previously said the truce would give pro-government fighters a chance to regroup.
In announcing the truce, spokesman for the coalition Brigadier General Ahmed Asseri said: "Military actions by coalition forces will be stopped, yet if Houthi militias and forces loyal to them may launch military operations or build up military movements in any area, they would be confronted by the coalition forces."
Asseri also said: “There is a commitment from the UN that the Houthi militias will accept [the] ceasefire.”
Ban Ki-moon, the UN secretary-general, said he urged all the the parties to "agree to and maintain the humanitarian pause for the sake of all the Yemeni people" and asked them to act in good faith throughout the pause.
The pro-government forces had battled retreating rebels on the northern outskirts of Yemen's second city of Aden on Sunday. Yemeni medical sources said a coalition air raid killed at least 35 civilians in the bombings.
According to the Saudi press agency, the ceasefire came at the request of Yemen's President Abd-Rabbu Mansour Hadi, who has taken refuge in the Saudi capital with much of his government.
Hadi wanted the truce for the "delivery and distribution of the maximum amount of humanitarian and medical aid", the agency said.
Anti-rebel fighters including Hadi loyalists have recaptured most of the southern port of Aden from the rebels after four months of war.
Two previous ceasefires failed to take hold.
An earlier Saudi-initiated humanitarian pause lasted for five days in May but the coalition resumed air strikes immediately after it expired, accusing the rebels of numerous violations.
A six-day UN-proposed truce which was due to begin just before midnight on July 10 also failed as clashes and coalition air strikes persisted.
Humanitarian crisis of immense magnitude looms in Yemen
The impoverished nation has been rocked by months of fighting between Houthi Shia rebels and Hadi loyalists, supported by the coalition, leaving thousands dead and 21 million people in need of urgent aid.
Hassan Boucenine, the head of mission for Yemen's Doctors Without Borders (MSF) told Al Jazeera a truce was urgently required by medics as there were now no medicines getting into the country besides those brought in by NGOs.
"In practice, more than half of the hospitals have stopped working," Boucenine said.
Iona Craig, an independent journalist, told Al Jazeera that people across the country were low on basic staples such as water, rice, flour, fruit, vegetables, and fuel.
"Ground blockades by the Houthi forces have been stopping aid and cutting off places like Aden and preventing food supplies and medical supplies from getting in," Craig said.
Source: Al Jazeera and agencies