Looks like the situation in Yemen is really starting to escalate.

Vast crowds have taken to the streets across Yemen to demand the immediate resignation of Ali Abdullah Saleh, the president, rather than the phased handover of power envisaged by a Gulf Arab plan expected to be signed on Sunday.

On Siteen Street, the largest road in Sanaa, the capital, 100,000 anti-government protesters flooded a 5km stretch to mark a "Friday of Loyalty to the Martyrs" commemorating the deaths of at least 142 protesters killed in the past three months.

During a Muslim prayer service, an imam read out a list of those killed in the protests.

"Enough blood, enough killing, just leave, leave, leave," the imam said during the sermon. "You have to submit to the people's demands."

Tens of thousands of people also gathered in the city in a pro-Saleh rally to mark a "Friday of Constitutional Legitimacy".

Read more: Massive rally in Yemen urges Saleh to go - Middle East - Al Jazeera English