Syrian opposition groups are stepping up calls for the Arab League to seek foreign intervention in Syria, since critics say the League's observer mission failed to curb violent outbreaks there.

Protesters took to the streets in several Syrian cities Friday after prayers, again calling for President Bashar al-Assad to step down.

Activists say security forces loyal to Mr. Assad patrolled the streets in a continuing crackdown against protests. Syrian activist Rami Abdul-Rahman told VOA at least four people people were killed in violence nationwide. He said three were civilians and one was a member of the security forces.

Arab leaders are to meet in Cairo Sunday to review a report by the observer team's Sudanese chief, and to decide whether to keep the team of about 165 monitors in Syria for another month.

The observers have been trying to determine whether the government is keeping its pledge to stop violently suppressing the uprising against Mr. Assad.

Human Rights Watch urged the Arab League Friday to release the observers' report to the public.

In a statement, the rights group said it has documented daily violations by security forces against protesters, and that it has evidence of Syrian government interference with the international monitors' work.

Syrians in Jordan gathered outside their country's embassy in Amman Friday, chanting anti-regime slogans and calling for U.N. intervention.

Syrian rights groups have criticized the observers' effectiveness, saying the Assad government has deceived the team and escalated its deadly attacks on the opposition since December 26, when the observers began their work.

Qatar's ruling emir has called for Arab troops to be deployed in Syria to stop the government crackdown. Syria has rejected the idea.

The United Nations says violence linked to the uprising has killed more than 5,400 people. Syria says “terrorists” have killed about 2,000 members of the security forces since the unrest began.

On Friday, French President Nicolas Sarkozy maintained France's non-interference stance on Syria, but said his government would not stand by if the bloodshed continues.

Russia and China have repeatedly refused to vote on a U.N. Security Council resolution on Syria, proposed by Western nations. Moscow, a longtime Damascus ally, refuses to place sanctions on Syria and insists the opposition is partly to blame for the chaos in the country.