Security has been beefed up at Los Angeles City Hall in response to a bomb threat directed at the mayor's office.

 

The bomb threat was made Monday, but "no evidence of a bomb or any sort of destructive device was located, nor has evidence been found lending credibility to this threat, said Sarah Hamilton, a spokeswoman for Mayor Antonio Villaraigosa.

 

The threat prompted the city's Department of General Services, which secures all the entrances to City Hall, to be on heightened alert, officials said.