Thirty-eight people were killed Tuesday in clashes between armed clansmen and government forces in a northern district of the Yemen capital Sanaa, according to a new toll from medical and government sources.
Three tribal dignitaries were among 24 supporters of powerful dissident tribal chief Sadek al-Ahmar who were killed, and dozens of others were wounded, a hospital source told AFP.
The defence ministry said on its website, citing the interior ministry, that 14 soldiers were killed and two were missing in the fighting.
An earlier toll said at least six were dead Tuesday in a second day of fighting between supporters of Sheikh Sadek al-Ahmar and forces loyal to embattled President Abdullah Saleh.
Fighters from Yemen's most powerful tribes and soldiers exchanged fire in the capital, using artillery shells, mortars in pitched street battles.
This was a sharp escalation in the uprising that is threatening to become a militia-led revolt after diplomatic efforts failed to get Saleh to step down.
Up to now, protesters filled the street with hundreds of thousands in demonstrations, demanding that Saleh resign after more than three decades in power.
After a mediation effort by Yemen's powerful neighbours in the Gulf Cooperation Council, backed by the US, failed this week, fighting erupted between tribes opposed to Saleh and security forces.