Police shot dead 12 people and injured dozens as they opened fire on demonstrators in Sanaa demanding President Ali Abdullah Saleh's resignation, medics said.

Security forces used live rounds as well as tear gas and water cannon to try to disperse hundreds of thousands of Saleh opponents trying to march on loyalist areas of the city center from their Change Square stronghold, killing 12 people, witnesses and medics said.

"We demand from the Security Council to force Saleh to leave power," read a banner carried by protesters, as others carried a effigy of Saleh being hanged and posters of killed demonstrator.

Barely two weeks after a drone killed US-born Anwar Al-Awlaki, a suspected US airstrike killed Friday a raft of top Al-Qaeda leaders, including the media chief of Al-Qaeda in the Arabian Peninsula, Egyptian Ibrahim Al-Banna'a.

Banna'a was "in charge of the media arm of AQAP" — the network's branch in Yemen — and one of the group's "most dangerous operatives," the Yemeni Defense Ministry said, denying as in past such cases that the raid was American.

The son of Awlaki, Abderrahman, 21, was also among the nine dead in the strikes that hit the militant-held town of Azzan in Shabwa, a member of Awlaki's tribe said.

Also killed was Sarhan Al-Quss'a, brother of Fahd Al-Quss'a, a leader of AQAP, who was on a US wanted list, the Awlaki tribesman said.

In northern Sanaa, 10 gunmen from the Hashid tribe which has sided with protesters against Saleh were killed in clashes with tribes loyal to the embattled president, a tribal source said.

The followers of tribal chief Sheikh Sadeq Al-Ahmar were killed in shelling of their position near Al-Hassaba area, stronghold of the Ahmar clan, a source in the sheikh's office said.

Al-Ahmar gunmen were locked on Saturday in fierce fighting with partisans of Sheikh Saghir bin Aziz, a tribal leader who has remained loyal to Saleh.