A new truce in Yemen was pierced within an hour as Saudi-led airstrikes hit targets in the southwestern city of Taiz following reports of ground fighting, security officials said.
The U.N.-declared truce that began after midnight Friday is meant to last through the end of the holy month of Ramadan and allow in desperately needed humanitarian aid for millions of people.
The officials said three airstrikes came after Shiite rebels and their allied forces clashed with rivals who have held pockets of resistance against the rebels' control of Taiz.
Witnesses reported the airstrikes. One airstrike targeted a military camp used by forces loyal to the rebels, while another hit a rebel convoy.
Both sides exchanged blame for violating the truce. Rebel officials said their rivals were using the truce to advance in Taiz. Fighters accused the rebels of trying to push them from the territories they hold.
All officials spoke on condition of anonymity because they were not authorized to report to the media amid a tense truce.
The pause announced Thursday comes just days after the U.N. warned that the Arab world's poorest country is "one step" from famine. Yemen relies on imports for the bulk of its food and fuel, but the coalition has imposed a near-complete air and sea blockade during the fighting. The rebels want the blockade lifted completely.
The U.N. this month declared its highest-level humanitarian emergency in Yemen on July 1. The U.N. humanitarian office says 80 percent of the population needs aid, and millions are close to famine.
Yemen's exiled government had wanted the rebels to withdraw from the cities and towns they had overrun since September as a precondition to a truce, but it came under pressure to agree to a halt in violence immediately.
Witnesses and officials said the truce was holding in the capital, Sanaa, as well as the country's second major city, Aden, and other cities. There were reports of minor fighting in parts of Aden, including missiles that landed near military installations in the in the north and west. Security officials said missiles fell near military installations controlled by rebels.
The officials, also speaking on condition of anonymity, said coalition airplanes flew over Aden.
Aid convoys had lined up outside Aden to be allowed in, but none had moved amid the reports of fighting.
More than 3,000 people have been killed in Yemen since March, when the Saudi-led, U.S.-backed coalition began airstrikes against the Houthi rebels who have seized control of the capital and other cities.
Houthi rebel officials had said they are committed to the truce. They spoke on condition of anonymity as they waited to see whether the other side, Yemen's exiled government and allied troops on the ground, would also commit.