Thousands of demonstrators are gathering in Yemen, some in support of a plan for government transition and others saying it is not enough.
Crowds are rallying in the capital Sana'a for a government-sponsored "Friday of Constitutional Legitimacy," while the opposition planned what it called a "Friday of Honoring Martyrs."
The Associated Press reported that security officers opened fire at protesters gathering in the port city of Hodeida, wounding three.
The turnouts came as doubts grew over an agreement between an opposition coalition and the government that calls for the president to hand over power.
The agreement was brokered by the Gulf Cooperation Council. It calls for President Ali Abdullah Saleh to hand over power to a deputy and resign within 30 days of signing the initiative. It would establish a unity government that would include opposition members.
Officials had said the agreement could be signed as early as Sunday in Saudi Arabia. But both sides have been wavering in recent days.
The opposition coalition says it fears the accord could be used by the president to crush the protests. The French news agency says that, for his part, Saleh expressed reservations about some Gulf Arab mediators, specifically Qatar.
On Wednesday, at least 13 people were killed in clashes between security forces and protesters at anti-government rallies demanding Saleh's immediate departure from office.
Some opposition groups say they oppose the agreement because it gives the president a month-long window to resign and because Saleh and his family would be granted immunity from prosecution.
However, EU foreign policy chief Catherine Ashton has welcomed the deal. She says the plan represents Yemen's "best chance" for addressing its economic, social and security challenges.
Some information for this report was provided by AP, AFP and Reuters.