Forces loyal to exiled Yemeni President Mansour Hadi have made advances in the port city of Aden. Meanwhile, Saudi-led airstrikes and clashes between Shiite rebels and Hadi loyalists have killed at least 60 people.
Pro-government fighters have pushed back the Houthi rebels from parts of the key southern city of Aden, the news website Aden al-Ghad said in a report on Sunday.
It has been the biggest advance by government forces in the city since fighting began between the two sides in March.
The "Southern Resistance" pro-Hadi fighters have cut off a major supply route for the Shiite rebels and seized several buildings in the city, including the Russian consulate and a Hadi residence, according to military sources. At least 11 Houthis and five pro-Hadi fighters died in the weekend clashes.
Fierce clashes have also been reported in the eastern oil-rich province of Mareb. At least 60 rebels were killed and 16 captured in the battle that erupted in the area on Saturday, a tribal leader told news agency DPA on condition of anonymity. Saudi warplanes also struck the Houthis' military outposts on Sunday in Serwah, which is about 40 kilometers west of Mareb.
Elsewhere, in the southwestern city of Taez, 10 Houthi fighters and four pro-Hadi militiamen were killed in a pre-dawn Sunday battle, the sources said.
The Shiite rebels, who are from Yemen's north, seized the capital Sanaa in September. Since then, they have been expanding their control across the impoverished Middle Eastern state, battling their way towards the strategically important southern parts and the oil-rich eastern territories.
Saudia Arabia, which wants internationally-recognized President Abd-Rabbu Mansour Hadi reinstated, launched an airstrike campaign along with eight Arab nations on March 26 to stop the advances of Iran-backed Houthis.
Meanwhile, the flow of aid into Yemen is still slow because of the restrictions imposed by the Saudi-led coalition on airspace and ports.
However, a coalition spokesman said efforts had been under way to step up aid after two loads of supplies from Qatar and the United Arab Emirates reached Yemen. "Other cargos will follow in the comings days," Brigadier General Ahmed al-Assiri told reporters in the Saudi capital Riyadh.
Aid agency Doctors Without Borders confirmed that "more than 70 tonnes of medical material" arrived in Sanaa on Saturday.
On Friday, the UN appealed for $274 million (253 million euros) in emergency humanitarian assistance for Yemen. According to the UN agency for refugees, more than 150,000 people have been displaced in Yemen since the start of the Saudi-led air campaign, while over 300,000 have fled their homes since the beginning of the conflict.
shs/kms (AFP, dpa)