Government forces backed by Saudi air force killed at least 17 al Qaeda fighters in Aden, the temporary base of President Abed Rabbo Mansour Hadi's government. Two civilians and three government troops were also killed in Sunday clashes.

Al Qaeda and "Islamic State" jihadists have taken advantage of the conflict to expand their control in Yemen, especially in areas where Hadi's forces have defeated the Iran-backed Shiite Houthi rebels.

About 300 heavily armed al Qaeda fighters are still entrenched in Aden's northern al Mansoura district. The police said in a statement that their battle against the "armed terrorist gangs in Mansoura will continue to ensure the safety of residents."

Battle for Taiz

Forces loyal to President Hadi are struggling to widen their control of the southwestern city of Taiz after breaking the siege of the Houthi rebels.

On Sunday, the Saudi-led coalition targeted a Houthi military convoy that was bringing reinforcements to the Shiite rebels.

At least 94 people have been killed in the offensive since Friday, including 24 rebels, nine government troops, and four civilians, according to medics and witnesses.

Some 200,000 people are trapped in Taez and desperately need humanitarian aid.

More than 6,000 people - half of them civilians - have died since the start of the Saudi military operation in Yemen in March 2015.

A Saudi-led coalition of Arab states launched an air campaign against the Houthis on March 26. Riyadh accuses Tehran of backing the rebels, who have made significant territorial gains in the impoverished Middle Eastern country, capturing the capital Sanaa and ousting internationally recognized President Hadi, who fled Yemen in 2014.

Yemeni ceasefire akin to Syria?

Visiting Saudi Arabia on Saturday, US Secretary of State John Kerry said he and Saudi Foreign Minister Abel al-Jubeir had agreed to work toward a ceasefire in Yemen in a process "similar" to the one that has largely held for two weeks in Syria.

Last month, the UN envoy for Yemen, Ismail Ould Cheikh Ahmed, said "deep divisions" were preventing progress toward a Yemeni ceasefire.

The Houthis and troops loyal to former Yemeni president and Houthi ally Ali Abdullah Saleh remain entrenched in much of the northern half of Yemen, including the capital, Sanaa.

Shamil Shams (Reuters, AFP, AP)