As the death toll mounted, the United States repeated its call for an end to the violence and a transition towards democracy.

More than 40 people were killed on Saturday in battles that hit several neighbourhoods across Sanaa, including Change Square, epicentre of anti-regime demonstrations, an activist from the protest organizing committee said.

He said hundreds of others had been wounded as the death toll spiralled to 173 people over the past week. State news agency Saba said 24 of Saleh's soldiers had also been killed.

"We slept and woke up to the non-stop sound of gunfire," one Sanaa resident told AFP as clashes between rival military units raged in the city centre.

As gunfire echoed around the capital, hundreds of thousands of people set out on a march from Change Square, which itself came under renewed fire from the security forces.

AFP