Abdulnasser Alseddik, Associated Press
In this Sunday, April 26, 2015 photo, a man carries a boy who was injured during a crossfire between tribal fighters and Shiite militia known as Houthis, in Taiz, Yemen. The fighting in Taiz between government forces and rebels was heaviest around government and security buildings in the city center, killing some 20 civilians and wounding dozens more, they said, adding that indiscriminately fired mortar rounds hit several private residences and landed near a hospital at one point.

SANAA, Yemen — Saudi-led airstrikes on Monday targeted Shiite rebels across Yemen, killing at least at least five people in the southern port city of Aden and striking a weapons depot in the rebel-held capital, officials and witnesses said.

The five were buried in the rubble when an airstrike hit two houses. The air raids in Aden had targeted a hill where the presidential palace is located and a separate gathering point for the rebels, known as Houthis, and allied military units loyal to former autocrat Ali Abdullah Saleh, witnesses said.

The airstrikes in the capital, Sanaa, hit Fag Atan mountain, the location of a major arms depot that officials have said was used to store ballistic missiles. At least 38 people were killed when similar air raids last week flattened nearby homes, burying residents under the rubble.

Saudi-led warplanes also carried out raids in the northern city of Saada and the western city of Taiz.

In Taiz, Yemen's third largest city, the Houthis and their allies deployed in large numbers overnight, triggering the airstrikes, witnesses and officials said.

The officials spoke on condition of anonymity because they were not authorized to speak to the press. The witnesses insisted on anonymity out of security concerns.

On Monday, street battles raged around government and security buildings in the center of Taiz, killing some 20 civilians and wounding dozens more.

The air campaign, launched March 26, is aimed at rolling back the rebels and restoring internationally recognized President Abed Rabbo Mansour Hadi, who fled the country last month. The United States is supporting the campaign but not taking direct military action.

The coalition announced the end of its initial operation, dubbed "Decisive Storm," last week and said it would be replaced by a more limited mission called "Renewal of Hope." The announcement raised hopes of a cease-fire, but the fighting has continued.