Lebanon's army is on alert -- setting up checkpoints and deploying patrols -- after a car bomb in Beirut Monday killed former Prime Minister Rafik Hariri and nine others.
The army declared a general mobilization late Monday as the nation began to observe three days of official mourning for Mr. Hariri, whose motorcade was attacked.
Opposition politicians in Lebanon have blamed Lebanese and Syrian officials for the attack, which wounded some 100 others. They also called for the government's resignation and the withdrawal of Syrian troops from Lebanon.
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. Western and Middle Eastern nations condemned the killing of the influential politician.
The White House also pledged to work with the U.N. Security Council to punish those responsible.