The Lebanese Cabinet is holding an emergency session Saturday, a day after a massive car bomb killed the country's police intelligence chief.
Eight people died and more than 80 were wounded in the blast Friday. The government has declared Saturday a national day of mourning.
Demonstrators have closed roads around the country to protest the bombing.
Lebanese media report Wissam al-Hassan, chief of police intelligence, was the target of Friday's car bomb.
Hassan led the investigation into a recent bomb plot that resulted in the arrest of a pro-Syrian Lebanese politician. He also led the probe that implicated Syria and Hezbollah in the killing of former prime minister Rafik Hariri.
No one has claimed responsibility for Friday's explosion. Some Lebanese officials blame Syrian President Bashar al-Assad for what they call Hassan's assassination.
Lebanon has seen a recent increase in violence related to the bloody Syrian civil war that has spilled over the border.