Thousands of demonstrators Sunday took to the streets of Casablanca, the country's largest city, in an antigovernment protest police struggled to disperse, driving into the crowd on motorcycles, armed with clubs.

A similar protest in the capital's twin city of Sale on Sunday also was violently disrupted, as was a demonstration in front of the Moroccan parliament Saturday.

Morocco's King Mohammed VI and the ruling elite, or makhzen, have so far avoided the massive "Arab Spring" uprisings that have swept other North African and Middle East countries, promising concessions and constitutional reforms in recent weeks as security forces successfully dispersed large crowds.

But protesters have grown both more assertive and organized in recent days, particularly the antigovernment Feb. 20 movement formed in the wake of uprisings in Tunisia, Libya and Egypt, which mounted Sunday's protest in Sale. On Sunday, well-known blogger Mamfakinch (which roughly translates as "We won't give up") posted Google maps of the protests online and live blogged their progress with photo and video updates. He posted witness accounts in French, including observations that police allowed pro-regime protests and even mixed with the crowds, but stopped those opposing the monarchy, accosting those with cameras, including journalists. "I can confirm there are wounded, clubbed in alleys," one witness said.

Both photos and videos posted online showed bloodied protesters collapsed in the streets of Casablanca's lower income Sbata neighborhood after allegedly being beaten by police. "Contrary to what has been said, the residents of Sbata do not reject the demonstrations," a witness told Mamfakinch, "I have never seen anything like it!"

Activists reported several arrests and more than a dozen injuries, some critical, during the protests, but those reports could not be independently confirmed.

-- Molly Hennessy-Fiske in Cairo

Video: (Top) Protesters take to the streets of Casablanca. (Middle and bottom) Moroccan police attempted to disperse crowds who gathered to protest in Casablanca and other Moroccan cities Sunday against the monarchy and ruling elite. Credit: Mamfakinch/YouTube.

Photo: A Moroccan protester collapsed in the streets of Casablanca's Sbata neighborhood during portests Sunday. Credit: Mamfakinch.