Adam Stuart Busby, 64, is accused by the FBI of sending additional bomb threats to courthouses throughout western Pennsylvania and making specific threats against U.S. Attorney David Hickton, ABC News reported.
Busby is being held in Dublin, Ireland, on charges he made bomb threats and hoaxes in Great Britain. He has been convicted previously of making bomb threats across Great Britain. He is a member of the terrorist group Scottish National Liberation Army, ABC said.
Hickton said an arrest warrant for Hickton will be filed with Interpol.
In a related case involving the University of Pittsburgh, two Ohio men who claimed to be members of the hacking group Anonymous were also charged in connection with the threats.
Alexander Waterland of Loveland and Brett Hudson of Hillsboro were indicted for hacking the university's computer system and releasing personal data.
The university was evacuated more than 130 times during the spring term because of bomb threats.
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