BEIRUT, Lebanon - The assassination of a prominent Lebanese politician Friday in a bombing in downtown Beirut shattered the illusion that Syria's tiny neighbor can avoid the violence on the other side of the border as its deeply divided political system continues to take sides in Syria's conflict.

Mohammed Chatah, a former finance minister and ambassador to the United States, was killed along with his bodyguard and at least four passers-by when a bomb targeted his convoy as he left a meeting of prominent pro-Syrian-rebel politicians in downtown Beirut.

The explosion was the first of its kind to strike Beirut's ritzy downtown since the 2005 car-bombing assassination of Chatah's close friend and political ally, former Prime Minister Rafik al-Hariri, and 21 other people. Friday's blast, just before 10 a.m. local time, destroyed several storefronts, blew out windows in exclusive condominiums and luxury hotels, and set nearly a dozen cars ablaze. The bomb rattled windows throughout the city, which has been on edge since two bombs struck the Hezbollah-controlled southern suburbs this year.

In Lebanese political circles, Chatah was seen as a moderate political figure and an economics-orientated technocrat from the Sunni Muslim-majority northern city of Tripoli. Compared with many other members of his political party, the Future Movement, he was considered a less bombastic voice despite his deep opposition to the Syrian regime of Bashar al-Assad and Assad's top Lebanese ally, the Shiite Muslim militant group Hezbollah.

The Future Movement, led by Hariri's son Saad, a former prime minister himself, has been adamant in its support for the Syrian rebels as well as very vocal about the role that Syria and Hezbollah are alleged to have played in the elder Hariri's death. Releasing a statement from exile in France, Saad Hariri, who refuses to return to Lebanon out of security concerns, declared that Chatah's killers were the same men who had killed his father.

Lebanon's support and funding for an international tribunal in the Hague, Netherlands, remain a viciously partisan affair, with Hezbollah and its backers - generally supporters of the Syria regime as well - adamant that the trial shouldn't be funded by the Lebanese government.

In the United States, Secretary of State John Kerry condemned the attack on behalf of President Obama. "This is a terrible loss for Lebanon, the Lebanese people and for the United States," Kerry said in a statement. "I had the privilege of spending many hours with Chatah . . . and I know he was a voice of reason, responsibility and moderation."