Photo: Yemeni Resistance in Taiz (YOL)

Airstrikes by the Saudi-led coalition targeting the country's Shiite rebels as well as fighting on the ground between rebels and pro-government fighters in the southern province of Taiz have killed at least 13 people and wounded dozens, Yemen officials said Friday.

Three children died in the airstrikes in the provincial capital of Taiz, while ground fighting on the city's outskirts killed a total of 10 fighters from the two sides, said security and medical officials who remain neutral in the conflict that has splintered Yemen.

Yemen's fighting pits the rebels, known as Houthis, and forces loyal to former President Ali Abdullah Saleh against the Saudi-backed and internationally recognized government forces as well as southern separatists, local militias and Sunni extremists.

The pro-government forces got a boost earlier this week with the return of Yemen's President Abed Rabbo Mansour Hadi, who came back to the country following nearly six months of exile in Saudi Arabia.

The Houthis, who control much of Taiz province, have over the past weeks laid siege in the to the city of Taiz, Yemen's third-largest, where pro-government troops have set up camp, independent security officials said. Friday's ground attack was an attempt to re-enter the city, the officials said.

The Houthis on Wednesday raided three international aid convoys traveling to war-torn Taiz with much-needed medicine and food from the Red Sea port of Hodeida, they said.

"It is almost impossible to send aid to Taiz," said Hassan Boucenine of the Geneva-based aid group Doctors Without Borders, also known as Medecins Sans Frontieres or MSF. "Until a couple of weeks ago, you could send some during the day, but not anymore," he added.

As a result, Taiz residents now have "no medicine or vegetables," said human rights activist Abdel-Baset al-Samei.

Ezz Eddin al-Asbahi, a minister for human rights in Hadi's Cabinet, denounced in Geneva on Friday "the crimes and violations by the Houthis and Saleh's forces ... taking place in Taiz."

The rebels fighting there "aim to sow hatred," the minister added. The Shiite rebels and pro-Saleh forces are "punishing the city for rebelling against them."

Taiz, where Saleh lived for a decade before he became president, is a predominantly Sunni city. All officials spoke on condition of anonymity because they were not authorized to talk to reporters. Houthi officials could not be immediately reached for comment.

The war in Yemen escalated in March when the Saudi-led coalition launched a campaign involving air strikes and ground troops against the Houthis and their allies. More than 2,100 civilians have been killed, according to U.N. estimates. The coalition recently has sought to retake the rebel-held capital, Sanaa, captured last September by the rebels.

AP