More than 80 protesters were arrested Saturday night after clashing with officers and vandalizing banks in Tel Aviv, in what was the latest effort to relaunch the social justice movement that mobilized an unprecedented number of Israelis against social inequalities last summer.

The demonstrators had gathered Saturday night to protest the arrest of 12 social activists a day earlier. Some blocked main roads and scuffled with police. Police say others shattered windows on five banks.

Israeli media reported that in one case, protesters charged inside a bank and set up a tent, the symbol of social protests that swept the country last summer.

Police spokesman Micky Rosenfeld said police made the arrests to prevent looting. He estimated there were 1,500 demonstrators in the protests, though media reports gave a number four times higher. In one video, a police officer was caught on tape pushing and strangling a demonstrator.

Activist leader Daphni Leef accused police of brutality, saying officers bruised and humiliated her when they detained her Friday. She was released on bail.

Meanwhile, the international human rights organization Amnesty International came out in defense of the protesters, and condemned what they termed police brutality. Amnesty activists issued a letter to Public Security Minister Yitzhak Aharonovitch on Sunday, Army Radio reported, saying, "The reports of police conduct toward the protesters in Tel Aviv over the last 48 hours raise a serious concern that not only were the rights of the protesters not protected, they were violently violated as well."

With regard to violence committed by the protesters, Amnesty said, "There is no room to compare this violence to the violence displayed by the police. The former is a violation of the law while the latter is a violation of human rights."