(CNN)A fire broke out at the Mt. Zion African Methodist Episcopal Church in Greeleyville, South Carolina, on Tuesday. Up to 50 firefighters fought to extinguish the blaze, a fire official said. As yet, authorities do not know what caused it, said Williamsburg County Fire Chief Randy Swinton. The local sheriff, local police and the South Carolina Law Enforcement Division have also responded to the fire at the traditionally black church. The FBI and five agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives is also investigating, said ATF Special Agent Tom Mangan. "Anytime there is a house of worship...