SANA'A // Yemen's most powerful tribal leader and a breakaway military group called on the nation yesterday to join them in the fight to end Ali Abdullah Saleh's 32-year rule as president.
"Tribes do not stay quiet when rights are being violated. Saleh has killed many innocent people, and we call on all the honest and Yemeni tribes to stand in the face of Saleh and fight him," said Sheikh Sadeq al Ahmar, head of the Hashed tribal federation.
Mr Saleh and Sheikh al Ahmar agreed to a truce on Saturday after five days of street fighting between government security forces and tribesmen. The most recent violence left at least 115 people dead and hundreds more wounded, forced thousands to flee the capital and pushed the country to the brink of civil war.
Yesterday there was no let-up in pressure on Mr Saleh from Yemen's tribes and dissident military units to step down after nearly a week of violence sparked by his refusal on May 22 to sign a transition deal brokered by the Gulf Co-operation Council. It was the third time he had abruptly backed away from the proposal.
There also were signs that another front in the battle for Yemen had erupted again, as up to 300 al Qa'eda militants seized control of Zinjibar, a town of more than 20,000 people near the shores of the Gulf of Aden and in the flashpoint province of Abyan.
A group of dissident generals led by General Ali Mohsen al Ahmar accused Mr Saleh of allowing the militants to seize Zinjibar to stoke fears in both regional and western capitals that al Qa'eda would take over the country if he acceded to demands to step down.
In a statement, the generals accused Mr Saleh of "surrendering Abyan to an armed terrorist group" and called on "the forces of the army to join the peaceful popular revolution". They also called on the army to fight the "terrorists" in Abyan.
As al Qa'eda militants consolidated their grip on Zinjibar, an uneasy peace held in the capital, 270 kilometres to the north-west. Pedestrians and cars returned to the streets where battles raged last week in the bloodiest fighting since pro-democracy unrest flared in January.
Sheikh al Ahmar's men handed back control of a government building to mediators as part of the ceasefire deal.
The lull did not deter the head of Bakeel, Yemen's largest tribe, from declaring his support for Sheikh al Ahmar and his Hashed fighters.
"If Saleh thinks that he will fight the al Ahmar family without us supporting them, then he is wrong," Ameen Okiami said. "Saleh must know that all Yemen's tribes will fight him to ensure that the Yemeni revolution stays as peaceful as possible."
Cracks in Yemen's military also appeared to widen as General Abdullah Ali Aleiwa, a former defence minister, urged government soldiers "not to follow orders to confront other army units or the people".
There were reports that a powerful Republican Guard run by Mr Saleh's son had defected to the opposition in a southern province. Abdul-Rahman Ahmed, a human rights activist, said a letter announcing the defection from Brigadier General Ibrahim al Jayfi, commander of the Guard's Ninth Brigade, was read to thousands of protesters in the provincial capital of Damar.
Generals and other senior military officers began to abandon the president after crackdowns on pro-democracy protesters started in force in March. Even so, yesterday's reported defection was the first by elite troops, which have been the core of Mr Saleh's grip on power.
Despite the pledges by powerful tribal heads, how long the truce would prevail in Sana'a remained highly uncertain after last week's killings of Hashed tribesmen by government security forces.
Ali Abdul Jabbar, director of the Dar Ashraf Research Centre, said: "Whether they avenge their killings today or in ten years, the tribes do not forget their blood." .
Though some tribes have a history of differences with Hashed, standing against Mr Saleh was a long awaited dream. Sheikh Mohammed Abulahoum, a Bakeel tribal leader, said: "It's not about tribes and loyalty; it's more about right and wrong."
Yemen has three main tribal groups, the Bakeel, the Hashed and the Midhaj, to which more than three in every five Yemenis belong. Mr Jabbar and other analysts say the tribes opposed to Mr Saleh are eager to prove that tribalism and modernity are not incompatible.
Sheikh Khaleb Ahmed, a Midhaj tribal leader, said: "Tribalism cares very much for people's rights, and that is why it continues to stay powerful. Tribes never accept oppression and never stand with [those who are] wrong. That's why we are standing against Saleh."
That opposition does not necessarily ensure that the president's tenure in power will be short-lived. Mr Saleh, a successful practitioner of tribal politics and himself a member of the Hashed, has been working to strengthen his alliance with rivals of the Al Ahmar family.
Ahmed Soufi, Mr Saleh's media adviser, said: "Who said that the Ahmar family represent the Hashed? A large number of tribal leaders from Hashed are allies with President Saleh. This fight is not between Hashed and the government. The Ahmar family are outlaws and no one is above the law."
* With additional reporting by Associated Press and Reuters