A two-day ceasefire after nearly two years of war in Yemen expired at midday (0900 GMT) on Monday and would not be renewed, a spokesman for a Saudi-led military coalition told al-Arabiya TV, with each side blaming the other for violations.
The 48-hour truce, announced unilaterally by the Saudi coalition on Friday, failed to halt fighting across the country between the Iran-aligned Houthis and Saudi-led forces, which intervened on the side of the exiled government in March 2015.
The 20-month conflict has killed more than 10,000 people and displaced more than three million.
Residents in the capital Sanaa said that Saudi-led coalition jets had bombed army bases on a mountain overlooking the city earlier on Monday, and the force of the explosions had shaken buildings in several city neighbourhoods.
Sanaa is controlled by the Houthis, who still hold vast swathes of Yemen despite the Saudi-led military campaign gaining territory and not succeeding in restoring President Abd-Rabbu Mansour Hadi to power.
Visiting neighbouring Oman last Tuesday, U.S. Secretary of State John Kerry announced that both sides had agreed to a deal whereby the Houthis would quit Yemen's major cities and the factions would form a national unity government.
But Hadi's government rejected the announcement that the warring parties had agreed to an open-ended truce and to work toward forming a joint government.
It said it was not consulted about the accord and objected to demands that the Houthis withdraw from cities they had captured since 2014.
The Houthis have also said the ceasefire was designed to undermine the agreement reached in Oman.
The Saudi coalition has made no comment on the deal.
Gulf Arab forces intervened in Yemen in March 2015, after the Houthis, backed by government troops loyal to former President Ali Abdullah Saleh, advanced on Hadi's temporary headquarters in Aden forcing him to flee to Saudi Arabia.