Yemeni tribesmen said fierce fighting to control three military posts killed 19 of their people and wounded dozens in a region south of Sanaa on Friday as clashes threatening to spark civil war spread outside the capital.

“There had been some skirmishes between the tribesmen supporting the youth revolution from time to time, but today it became a big armed confrontation,” said Hamid Asim, a tribal leader from the Nahm region.

In Sanaa, tens of thousands of people gathered after Friday prayers for what they said would be a “Friday of Peaceful Revolution” against President Ali Abdullah Saleh, releasing white doves and carrying the coffins of about 30 people killed in clashes this week.

But the turnout for the rally, inspired by the Egyptian and Tunisian revolutions, was lower than in previous weeks. Many people have fled Sanaa, and the government closed roads around the capital to keep out tribes trying to reinforce the Hashed tribe, led by Sadiq al-Ahmar, which has been battling forces in the city that are loyal to Saleh.

Machine-gun fire rattled across Sanaa, and sporadic explosions were heard near a protest site where thousands of people demanding Saleh’s departure are still camped.

Fighting eased off later Friday after mediation efforts under which the Ahmar tribe evacuated government ministry buildings they had seized during clashes this week in return for a cease-fire and troops’ pulling out from their area.

“We are now in mediation, and there has been a cease-fire between the two sides,” Ahmar told protesters in Change Square. “But if Ali Abdullah Saleh returns [to fighting], then we are ready.”

The weeklong battles, the worst since unrest erupted in January, have enabled Saleh to recapture the initiative in the standoff, with the threat of civil war overshadowing the protest movement. But many protesters remained determined to see him out.

“We are here to renew our resolve for a peaceful revolution,” Yahya Abdulla said at the anti-Saleh camp. “We reject violence or being dragged into civil war.”

Worries are growing that Yemen, already a safe haven for al-Qaeda and on the verge of financial ruin, could deteriorate into a failed state that would erode regional security and pose a serious risk to its neighbor Saudi Arabia, the world’s No. 1 oil exporter.

— Reuters