Nine tribesmen were killed as they clashed with republican guards in an army camp outside Sana'a on Friday, as fighting in Yemen between armed tribesmen and security forces calmed after five days of violence, dpa reported.
News website the Yemen Post said the nine died when armed members of Arhab tribe clashed with the guards loyal to embattled President Ali Abdullah Saleh. However, other local media reports said that the Yemeni air force bombed the army camp, around 100 kilometres outside the capital, after it was seized by rebel tribesmen.
Planes shelled the area after the clashes, the reports said.
At least 60 people have died in recent days in clashes between loyalists to prominent tribe leader Sheikh Sadiq al-Ahmar and security forces, with dozens of families forced to flee the area.
Many ministries and government offices, located near the clashes in al-Hasaba district of Sana'a, were shut down.
Al-Ahmar said on Friday that there was a truce between his fighters and security forces in Sanaa, but he was ready for war if Saleh wants one.
At a funeral for some of his fighters, al-Ahmar said that "if Saleh's regime wants a peaceful revolution, we are ready for that. If he chooses war, we will fight him."
The clashes first erupted last Monday, after Saleh for a third time refused to sign a Gulf-brokered power transfer agreement that would have seen him step down in return for immunity from prosecution.
Al-Ahmar is the head of the Hashid tribe, to which Saleh belongs. Saleh already ordered the arrest of al-Ahmar.
The Joint Meeting Parties (JMP), Yemen's main opposition bloc, have held the government accountable for targeting tribal leaders, calling on president Saleh to immediately stop his forces.
The JMP also called for peace, as Yemen appears to totter on the brink of outright civil war.
Opposition and activists said they will continue with their anti-government protests to topple President Saleh and his regime, as tens of thousands of anti-government protesters took to the streets on Friday across Yemen.
"I am going to the protest to tell the world that I want to change the regime and to make sure our demand is fulfilled peacefully, not through wars," says Abdullah, 31, in Sana'a.
Saleh has defiantly clung to power despite months of mass protests calling for him to step down after 32 years in office.