Yemeni loyalist forces fought street battles with guards from a powerful tribal federation whose leader has sided with protesters demanding an end to President Ali Abdullah Saleh's rule, witnesses said today
The opposition warned that such attacks by loyalists, which residents said targeted the mansion of tribal leader Sadiq al-Ahmar, could spark a civil war.
At least nine people were killed in the clashes, which dimmed prospects for a political solution to end a transition of power tussle nearly four-month-old revolt inspired by protests that swept aside the leaders of Egypt and Tunisia.
"The clashes were violent. The sound of machinegun and mortar fire could be heard everywhere. I saw smoke rising from the entrance of the interior ministry," one witness said.
Nine people were killed and 30 wounded "because of the aggression launched by the Ahmars and their gangs", an official told the Defence Ministry website, without giving details.
The clashes followed the collapse on Sunday of a transition deal mediated by Gulf neighbours that Saleh was to have signed that would have given him immunity from prosecution.
The shooting, in the sandbagged streets near a fortified mansion belonging to the wealthy and politically powerful Ahmar clan, pitted loyalist forces against guards of Sadiq al-Ahmar, head of a tribal group from which Saleh also hails.
"The attack on (Ahmar's) house ... is a symptom of the hysteria experienced by President Saleh and his entourage and their insistence on engulfing the country in a civil war," the opposition coalition said in a statement.
Several mediators, including a security police head, were injured in the attack on the Ahmar house, where they had gathered to try to end the fighting, an opposition leader said.
Ahmar's house and the adjacent residence of another Ahmar tribal leader, were damaged in the attacks, residents said.
Footage, which Al Jazeera television said was from inside the house, showed dazed and bloodied tribal guards carrying wounded comrades across ornate halls as dust filled the air.
Saleh loyalists and army forces used mortars and rocket-propelled grenades in the attack, witnesses told Reuters.
Four tribal guards were killed, and six other people were wounded, an opposition leader said. Fighting in the same area of the capital yesterday killed seven people.
The government accused Ahmar's men of "attempting a coup" by attacking the Interior Ministry and several other government and police buildings, the state news agency Saba reported.
Agencies