ATLANTA - The FBI received a letter Monday claiming responsibility for both the abortion clinic bombings in Atlanta last month and Friday's bombing at a gay and lesbian nightclub.
The letter, purportedly from a group called the Army of God, was mailed to the Reuters news agency Saturday and was turned over to the FBI on Monday.
FBI spokesman Jay Spadafore would not comment on the authenticity of the letter. Robert Basler, Reuters' domestic news editor in Washington, D.C., described it as "handwritten, 2« pages long, and unsigned."
The letter threatened "total war" against the federal government, said abortion would not be tolerated and promised future attacks on homosexuals. It also sought to set up a system so that claims of responsibility could be confirmed after future bombings, Reuters reported.
"We're taking it seriously. We're looking into the validity of the letter and the claims that they're making," said Pamela Swanson, a spokeswoman for the Georgia Bureau of Investigation.
The Army of God has produced an underground manual that describes how to blow up abortion clinics.
A nail-laden device exploded Friday on a rear patio area of The Otherside Lounge, injuring five people. Police found a second bomb shortly after arriving at the scene. It was detonated with a remote-controlled robot.
Authorities continue to investigate possible links between the nightclub bombing, the two blasts at a Sandy Springs abortion clinic on Jan. 16, and a bomb explosion at Centennial Olympic Park last summer.
Shrapnel and parts of the bomb were being "discovered several hundred feet away" from the nightclub, including on the tops of buildings, said Bobby Browning, spokesman for the Bureau of Alcohol, Tobacco and Firearms.
"I know it's obvious to everyone, so I will go ahead and confirm it: there were nails in some of the bombs in all three incidents. There were not nails in every device, but there were nails in at least one at each incident," Browning said.
"We're examining the possibility that the same person or persons may have conducted two or more of the three bombing incidents. But we can't exclude the possibility that it's just happenstance that the devices are very similar, or a copycat," Browning said.
More than 50 federal agents have been assigned to the case, including the same task force that investigated the bombing at the Atlanta Northside Family Planning clinic.