Geagea, leader of the opposition Lebanese Forces party, said Wednesday that a sniper fired at his residence from roughly a half-mile away. The attempted assassination, he claimed, was an indication the era of political killings in Lebanon hasn't ended, The Daily Star newspaper in Lebanon reports.
The U.S. State Department said it was concerned about the incident, calling on Beirut to launch a thorough investigation.
"While we do not know who was behind the attack at this time, we are deeply concerned that Mr. Geagea may have been targeted because of his outspoken criticism of the (Syrian President Bashar) Assad regime's murderous repression and Hezbollah's destabilizing actions in Lebanon," State Department spokesman Mark Toner said in a statement.
The Lebanese Forces party belongs to the March 14 opposition slate. The ruling March 8 coalition includes Hezbollah lawmakers.
A statement from the party warned that Lebanon "might be taking a dangerous turn" and other assassination attempts are likely.
Geagea last year accused Syria of playing a role in kidnapping six Estonian bicyclists in Lebanon.