"We strongly condemn the terrorist bombing in Beirut today that killed a police captain and many other Lebanese," White House press secretary Dana Perino said, calling the explosion an attack by those seeking to "undermine Lebanon's institutions and democratic processes."
Lebanese officials say they believe top police investigator Wissam Eid, who died in the blast, was the target. Officials reported at least six people died, the Voice of America said.
Eid had just met with members of the United Nations tribunal investigating the death of former Lebanese Prime Minister Rafiq al Hariri when the car bomb detonated.
Ashraf Rifi, head of Lebanon's national police force, said he thought Eid's death was meant to be a "message to Lebanon's police and investigating community."