By AHMED AL-HAJ

SANAA, Yemen (AP) – Deadly street battles raged in Yemen’s third-largest city on Sunday, as airstrikes by the Saudi-led coalition battling Shiite rebels struck targets in several cities, security officials said.

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.

Reached by telephone, Taiz residents described relentless artillery, tank and heavy machine gun fire blasting through the city as families sought shelter wherever they could.

“It’s like our homes have become a military target, they are killing us in cold blood,” said resident Tawfiq Al Maamari. “We left our homes with our children because the missiles are raining down on us without mercy.”

The continued airstrikes and combat between rival factions on the ground underline how a negotiated peace remains elusive in the Arab world’s poorest country, despite a Saudi announcement last week that coalition operations would scale down and shift to focus on diplomacy, humanitarian and counter-terrorism issues. Both sides have said they welcome a return to dialogue.

The Shiite rebels, known as Houthis, are allied with military units loyal to former President Ali Abdullah Saleh.

Fighting continued across the country on Sunday, with airstrikes hitting the capital, Sanaa, as well as the cities of Dhamar, Marib, Aden, Shabwa, Hajjah, Saada, Ibb, and Lahj, the officials said. In Sanaa they began just after midnight, hitting a military base known to be an arms depot on the mountainous city outskirts, as well as sites near the presidential palace where weapons were being moved.

In the southern port city of Aden, officials said air raids targeted rebels as street fighting between them and forces loyal to embattled President Abed Rabbo Mansour Hadi continued. West of Aden, military officials said the Houthis and pro-Saleh forces captured an area leading up to the strategic Bab al-Mandab strait, which overlooks the entrance to the Red Sea, a key global shipping route.

The officials all spoke on condition of anonymity because they were not authorized to brief journalists.

Although Hadi is Yemen’s internationally recognized leader, he was forced to flee the capital and later fled the country as the Houthis advanced toward his stronghold of Aden last month. The Saudi-led coalition began conducting airstrikes against rebel positions on March 26.

Hadi is now in the Saudi capital of Riyadh. The Houthis still control much of the country. The Sunni Arab countries in the coalition and their Western supporters say the Houthis get their arms from Shiite powerhouse Iran, something both Tehran and the rebels deny.

The United Nations said Friday that the war has killed over 550 civilians in the past month, including 115 children.