Thousands of Yemenis gathered in the capital Sana'a on Sunday to protest the passage of a law giving President Ali Abdullah Saleh immunity from prosecution.

Yemen's parliament formally approved the law on Saturday. It grants Mr. Saleh complete immunity from legal and judicial prosecution for any alleged crimes committed during his 33-year rule, in return for stepping down.

It also grants a controversial partial immunity to the president's political aides, although last-minute amendments reduced the scope of that amnesty.

The new law is part of a deal brokered by neighboring Gulf nations aimed at ending months of political turmoil. The deal was signed in November.

The immunity law sparked an outcry by pro-democracy activists who have driven the nearly year-long revolution in Yemen.

They are calling for the president to stand trial for a violent crackdown on anti-government protests in which hundreds of people died.

Human Rights Watch also criticized passage of the law, saying in a statement that it “sends the disgraceful message that there is no consequence for killing those who express dissent.”

Under the Gulf deal, Mr. Saleh has handed authority to Vice President Abed Rabbo Mansour Hadi. Hadi is the consensus candidate of major parties in a presidential election scheduled for February.