Fighting broke out on the outskirts of Yemen's port city of Hodeidah on Friday, residents said, a day after a ceasefire agreement was reached by the warring parties at UN-sponsored peace talks.
One resident told Reuters he could hear the sound of missiles and automatic gunfire in the direction of the eastern 7th July suburb of the Houthi-held city, on whose outskirts Yemeni forces backed by a Saudi-led coalition have massed.
The Iranian-aligned Houthi movement and the Saudi-backed government had agreed after a week of consultations in Sweden to cease fighting in the Red Sea city and withdraw their troops.
It was the first significant breakthrough for UN-led peace efforts to pave the way for political negotiations to end the nearly four-year-old war that has killed tens of thousands of people and pushed Yemen to the brink of famine.
Envoy Martin Griffiths said at the end of the talks that both parties would withdraw "within days" from the port, a lifeline for millions facing starvation, and then from the city. International monitors would be deployed and all armed forces would pull back completely within 21 days.
Griffiths told the UN Security Council on Friday that a robust monitoring regime was urgently needed in Hodeidah to oversee compliance with the truce.
Such a monitoring mission needs the backing of the Security Council in a resolution, diplomats said.