Yemen's president Ali Abdullah Saleh is under growing pressure to quit after the chiefs of two of the country most influential tribes abandoned him and joined the anti-regime movement. Powerful tribal leaders, including those of the Hashid and Baqil, vowed to join protests against Saleh at a gathering north of the capital, a tribal source was quoted as saying by AFP. "I have announced my resignation from the General People's Congress in protest at the repression of peaceful demonstrators in Sanaa, Taez and Aden," Hashid tribal chief Sheikh Hussein bin Abdullah al-Ahmar said.
The Hashids are considered Yemen's most powerful tribal confederation and include nine clans.
The two tribes announced they would support the popular uprising against Saleh.
At least 19 people have now been killed in almost daily clashes during anti-regime protests since they started on February 16. Medics said security forces used live ammunition on a demonstration in the southern city of Aden, raising the death toll to four on Saturday from just one rally with 40 others wounded. They identified three of the dead as demonstrator Mohammed Ahmed Saleh, 17; Hael Walid, 21, and Salem Bashaj, an employee at the state electricity company who was shot outside his home.