Lebanon's Shi'ite militant group Hezbollah and its allies have called for a mass protest on Friday to demand a new government.
The groups issued a statement Thursday, calling for a peaceful sit-in protest in central Beirut.
The Hezbollah-led opposition had threatened a mass protest last week, but postponed it following the November 21 assassination of anti-Syrian politician Pierre Gemayel.
Hezbollah and its pro-Syrian allies say Lebanese Prime Minister Fuad Siniora's government violates power sharing arrangements. Earlier this month, six ministers from the Hezbollah and Amal parties quit the government because demands for more power were not met.
In other development, Lebanon's government earlier this week formally backed plans for a U.N. international court to try suspects in the 2005 assassination of former Prime Minister Rafik Hariri - a move that angered the pro-Syrian opposition.
A U.N. investigation into the Hariri murder implicated several pro-Syrian security officials. Supporters of the late prime minister accuse Syria of direct involvement. Damascus denies the charge.
The U.N. Security Council says the Hariri court could also help with the investigation into the Gemayel killing.
Some information for this report was provided by AFP, AP and Reuters.