A four-member team from the U.S. Federal Bureau of Investigation (FBI) was seen Friday searching the site where Samir Kassir was killed the previous day by a bomb placed in his car, dpa reported. Hundreds of Lebanese journalists, family members and opposition officials meanwhile maintained a vigil in downtown Beirut to mourn Kassir. The crowd carrying candles and portraits of Kassir gathered around the statue of the Martyr, chanting "freedom, freedom". A large portrait of Kassir raised above the statue read: "Kassir is the martyr of the uprising for independence", reported dpa. The FBI men, wearing white overalls and carrying cameras, were busy searching the site of Thursday's bombing and taking samples. They refused to speak to any reporters, but Lebanese security sources confirmed to dpa that "the team are indeed involved in the investigation". During the operation, Kassir's wife Gizelle Khoury was also at the site. She did not speak to the FBI agents. Lebanese justice minister Khaled Qabbani confirmed to dpa that Lebanon had requested the help of U.S. and French experts in the investigation. According to Lebanese security sources five French police experts were to go to Lebanon late Friday to help in the probe, following a request by Lebanese authorities. Kassir, originally Palestinian, held dual Lebanese-French nationality. The 45-year-old was assassinated in Ashrafiyeh neighbourhood in East Beirut. --SP 2156 Local Time 1856 GMT