Yemen unrest: Protesters wounded in Taiz
Security forces have fired on protesters calling for President Ali Abdullah Saleh step down in the southern city of Taiz, activists say.
They said at least 10 demonstrators were injured in the city, which has been a focus of recent protests.
Mr Saleh is clinging to power despite months of protests against his 30-year rule.
Earlier, troops reportedly shelled an area of the capital that is home to a tribal chief opposed to the president.
The fighting, which erupted in Sanaa early on Thursday, left three dead and five wounded, officials said.
Mr Saleh was gravely injured in an attack on his palace in June and has been recuperating in Saudi Arabia.
A recent UN report said Yemen risked sliding into civil war unless political unrest was resolved swiftly.
There was also violence in the southern city of Aden early on Thursday, where one young boy was killed in a gun battle following an attack on the intelligence headquarters and a police base.