The blast occurred as worshippers left the Salman Mosque after Friday prayers, officials and security sources said.
It was not known who planted the bomb near the door of the mosque, but the northwestern province has been rocked by sporadic violence since a conflict broke out in 2004 between government forces and rebels loyal to Abdul-Malik al-Houthi.
Houthi, a member of the Zaydi sect of Shi'ite Islam, denied any involvement in the attack, which he said was aimed at undoing efforts to broker a lasting peace in Saada.
"We criticise and condemn this regrettable incident ... We deny completely any role in this incident. It is not part of our ethics to target any mosque or any worshippers at all," he told Al Jazeera television by telephone from Saada.
"We believe that someone is trying to blow up a war and foil all the peace efforts through these incidents ... The real target of these incidents is us, the people of Saada."
Yemen has witnessed attacks by different groups targeting everything from tourists and embassies to government offices and oil pipelines or shipping in recent years, but attacks on mosques were virtually unheard of until Friday.
Sunni Muslims form a majority of Yemen's 19 million population, while most of the rest, including Houthi and his supporters, are Zaydis. But Yemenis proudly say that it is not unusual for members of both communities to pray together.
The security source said that the imam of the mosque, Askar Zaayl, was also the office manager of Ali Mohsen, Yemen's northern military commander who has led the government's fight against rebels loyal to Houthi.
Mohsen was not in the mosque at the time of the blast, though other Yemeni officers were.
Last Mod: 02 Mayıs 2008, 17:41