Witnesses in Yemen's capital, Sana'a, say fighting has erupted for a second day between government forces and opposition tribesmen of the al-Ahmar clan.

The witnesses say both sides exchanged fire in Sana'a's Hassaba district on Saturday, but no casualties were reported. Yemeni government forces and al-Ahmar tribesman also fired at each other in the area on Friday. The fighting in Hassaba has forced Yemeni authorities to divert flights away from the nearby Sana'a international airport.

The al-Ahmar clan is one of the most powerful within Yemen's main tribal confederation, Hashid. Its leaders turned against Yemeni President Ali Abdullah Saleh in March, siding with opposition activists leading a nationwide uprising against his 33-year autocratic rule.

Witnesses say pro-Saleh Republican Guards fired on anti-government protesters in the southern city of Taiz on Saturday, killing one and wounding three others. Taiz has been a major center of the uprising.

Mr. Saleh has been receiving medical treatment in Saudi Arabia since suffering severe burns in a June 3 bomb attack on his presidential compound that also wounded other key officials. He has refused to step down while his deputy leads the country in his absence.

A Yemeni official told foreign news agencies that Yemen's prime minister, who also was wounded in the June 3 attack, left a Saudi hospital on Saturday. The official said Ali Mohamed Megawar relocated to a Saudi government residence to continue his recuperation from the bombing.