Security official says troops loyal to ex-president Saleh allowed prisoners to escape amid clashes in prison in Taiz.
At least 38 people have been killed, including eight children, and dozens more injured as a result of a suspected coalition air strike at a wedding hall in southwest Yemen.
Monday’s air strike struck the wedding hall in the village of al-Wahijah, according to Yemeni security officials.
Along with the bodies of the dead, the injured were taken to the nearby port city of Mokha, which is reportedly controlled by Houthi rebels.
Speaking to the Associated Press, a senior government official described the air strike as a “mistake”.
The Arab coalition has been carrying out air strikes against Houthi fighters since March.
Speaking to Reuters, spokesman Brigadier-General Ahmed al-Asseri denied the coalition’s involvement. “There have been no air operations by the coalition in that area for three days,” he said. “This is totally false news.”
Last week, Yemen’s internationally recognised President Abd-Rabbu Mansour Hadi returned from Saudi Arabia, where he has been in exile since fleeing in March as the Houthi rebels made gains.
“As the fighting flares up in different parts of the country – particularly today in Sanaa, Taiz and Marib – we are expecting more casualties,” said Al Jazeera’s Hashem Ahelbarra.
“We are talking about a huge area in Yemen where there has been some intense fighting, in particular, air strikes were stepped up recently to push the Houthis out from those urban areas,” said our correspondent.
Meanwhile, a senior Saudi officer and another border guard were killed on Friday in a gunfight after a landmine blast along the frontier with Yemen, the Saudi interior ministry said in a statement.
Colonel Hassan Ghasoum Ageeli, one of the most senior Saudi officials killed throughout the conflict, died after coming under “heavy shooting from several locations inside the Yemen border”.
In late August, an air raid struck a bottled-water factory in the northern province of Hajja, killing 17 civilians and 14 rebel fighters.
Warplanes in July attacked the homes of employees of a power plant in Mokha, killing 65 civilians, while a raid on a dairy plant in the Red Sea port city of Hodeida in April left 35 civilians dead.