Photo: Yemeni child sitting on the ruins of his home that was bombed by airstrikes

Saudi-led coalition airstrikes resumed on rebel positions across Yemen Monday as fighting intensified hours after a five-day humanitarian cease-fire expired to enable the delivery of desperately needed aid.

Airstrikes hit rebel positions early Monday in the southern seaport of Aden and the northern city of Saada, a stronghold of the Iranian-backed Houthi rebels near Yemen’s border with Saudi Arabia, residents said.

Civilians in both Saada and Aden complained that basic foodstuffs, medical supplies and other desperately-needed aid had not reached them during the pause in fighting. Residents worried that the renewal of fighting would further impede relief efforts.

“There is still no fuel available and an extreme shortage of food,” said Ghassan Salah, a civilian living in Aden. “Some families have received [aid], some haven’t. Government officials who are supposed to distribute it free sometimes sell it. Nothing has improved.”

Aid groups have complained that the fighting has blocked roads needed to deliver humanitarian supplies.

Saudi foreign minister Adel al-Jubeir Monday accused the Houthis of blocking civilian access to aid, and expressed regret that the cease-fire had failed to achieve its humanitarian goals.

In a statement carried by the official Saudi Press Agency, Mr. al-Jubeir said: “The coalition would respond strongly and decisively if the truce continues to be violated and denying the delivery of humanitarian aid to the Yemeni people.”

Each side accused the other of violations throughout the cease-fire, which ended Sunday night with ground clashes throughout the country between Houthi rebels and Saudi-backed Yemeni militias.

U.S. Secretary of State John Kerry said Monday the U.S. favored an extension of the truce but added that an agreement would be difficult to reach due to Houthi breaches of the cease-fire.

Talks aimed at ending the nearly eight-week war began Sunday in the Saudi capital Riyadh among various Yemeni factions, but Houthi rebels have said they wouldn’t participate in any Saudi-led political process. They have backed proposals for talks sponsored by the United Nations.

Speaking in the South Korean capital Mr. Kerry said the U.S. would encourage the U.N. talks.

“The only resolution to this is going to come from a political arrangement by which Yemenis themselves—without external interference—are able to come to accommodation in order to decide their future,” Mr. Kerry told reporters. “That is what the U.N. is working toward and what the United States is working toward.”

Saudi Arabia is leading a coalition of nine other countries to unseat the Houthi rebels from power and restore Abed Rabbo Mansour Hadi to the presidency. The coalition began a naval and aerial blockade of Yemen on March 26.

Iran’s state-owned Tasnim news agency reported Monday that Iranian warships are escorting a ship carrying aid donated by the Iranian government as it traverses the Gulf of Aden.

It said the ship plans to dock at a seaport in western Yemen in the next few days.

U.S. officials denied earlier reports that Iranian war vessels were accompanying the ship. Saudi Arabia has in the past blocked aid deliveries from Tehran, even bombing San’a airport last month to prevent one such attempt.

WSJ