Lebanese troops are on high alert as the country began three days of official mourning for former Prime Minister Rafik Hariri, who was killed in a car bomb attack in Beirut Monday.
The army set up checkpoints and deployed patrols in Beirut. The streets of the capital are virtually empty as schools, shops and private and public institutions are closed.
Mr. Hariri's funeral is planned for Wednesday. Nations around the world condemned the killing of the influential politician.
The White House pledged to work with the U.N. Security Council to punish those responsible. Lebanese opposition politicians blamed Lebanese and Syrian officials and called for the government's resignation and the withdrawal of Syrian troops from Lebanon.
At least 13 other people were killed and about 120 wounded in Monday's bomb attack on Mr. Hariri's motorcade. In a video broadcast on Al Jazeera television, an unknown Islamic group claimed responsibility for the bombing.
Lebanese officials identified a man in the tape as a Palestinian who lives in Beirut. He remains at large.
Information for this report is provided by AP and Reuters.