Lebanon was preparing Sunday for the funeral of former finance minister Mohammed Shattah, an opposition politician who was killed in a car bombing in Beirut two days ago, dpa reported.
Shattah, a Sunni Muslim, was a close aide to former prime minister Saad Hariri and a critic of Syrian President Bashar al-Assad and his ally the Lebanese Shiite movement Hezbollah.
Some members of Shattah's March 14 coalition, which includes Muslims and Christians, have blamed the Syrian government and Hezbollah for the assassination.
Both have denied any involvement.
March 14 has urged its supporters to turn up in large numbers for Shattah's funeral to send a strong political message to its opponents.
Shattah's funeral ceremony will take place following mid-day prayers at the Mohammad al-Amin Mosque in Beirut.
Shattah was a key adviser to Hariri and main strategist within March 14. He will be buried near former premier Rafik Hariri, Saad Hariri's father who was also killed in a car bomb in Beirut in 2005.
The car bombing on Friday killed six other people and was the latest in a series of deadly attacks in Beirut, including twin suicide bombings targeting the Iranian embassy last month.
Hezbollah, which is backed by Shiite Iran, has sent fighters to Syria to help forces loyal to al-Assad against largely Sunni rebels backed by Saudi Arabia and other Gulf states.
Its military involvement in Syria has heightened sectarian tensions in Lebanon, prompting bouts of violence between supporters and opponents of al-Assad.
Shattah's killing came 20 days before a UN tribunal investigating Rafik Hariri's assassination was due to start trying suspects in The Hague.
Five Hezbollah members will be tried in absentia on charges linked to the assassination.