A look at anti-government protests, political unrest and key developments in the Middle East on Friday:
Moammar Gadhafi's regime gains momentum with the capture of a key city near Tripoli after days of fierce fighting with rebels.
The battle for Zawiya has emerged as a key test in the government's ability to maintain its hold on the Libyan capital and surrounding areas.
A massive show of force snuffs out a Facebook-based effort to stage unprecedented pro-democracy protests in the capital of Saudi Arabia, Riyadh.
In the heavily Shiite eastern Saudi city of Qatif, armored personnel carriers and dozens of officers in riot gear surround several hundred demonstrators shouting calls for reforms and equality between the sects.
Yemen's largest demonstrations in a month are met by police gunfire that left at least six protesters injured and seem certain to fuel more anger against the deeply unpopular U.S.-allied president. Hundreds of thousands of protesters gather in Yemen's four largest provinces.
Security forces reinforced by pro-government mobs fire rubber bullets and tear gas to scatter protesters near Bahrain's royal palace. Conflict is deepening between Sunni Muslims backing the ruling system and Shiites demanding it give up its monopoly on power.
Tunisia's Interior Ministry says a new eruption of violence between police and protesters has killed two and injured 20. The violence comes as Tunisia's interim government is trying to restore stability after deadly protests that drove out longtime leader Zine El Abidine Ben Ali in January. That prompted uprisings around the Arab world.