SAN DIEGO – A UCSD employee who was fired from his job as a lab technician last week was arrested yesterday in connection with a bomb hoax Wednesday that targeted a research building on the La Jolla campus where he formerly worked.

Timothy Bryon Kalka, 50, of San Diego was arrested about 6 a.m. at his San Diego residence by members of the Joint Terrorism Task Force, said FBI Special Agent Darrell Foxworth.

Kalka was charged in a federal arrest warrant with providing false information or engaging in hoax activities pertaining to explosives. He was booked into the Metropolitan Correctional Center in downtown San Diego and was expected to appear tomorrow in federal court.

Foxworth said the arrest was the “direct result” of several leads from the public that followed media broadcasts Thursday of a recording of a bomb threat phoned to the University of California San Diego.

Some people who heard the recording “thought they recognized a voice” and called authorities, Foxworth said.

The FBI had also released to the media a copy of a letter that the university had received Wednesday that stated a group called the Animal Liberation Front would detonate explosive devices at research buildings on the campus if research animals were not evacuated.

Foxworth said yesterday that he had no information on a possible relationship between Kalka and the animal-rights group.

Kalka worked at the Leichtag Family Foundation Biomedical Research Building, which is where a suspicious device was found about 10:30 a.m. Wednesday. He had been fired by UCSD Nov. 30, the FBI said.

Barry Jagoda, a UCSD spokesman, said yesterday that he did not have information about Kalka's arrest or firing, and that university personnel matters are private.

All medical buildings on campus were evacuated Wednesday until an investigation determined the suspicious device was not a bomb.