Police say there is "no evidence" to suggest there is any danger to the public after a threat was made to bomb Toronto City Hall unless Mayor Rob Ford and his brother Coun. Doug Ford resign.

Officers were dispatched to the building after city hall security notified police of the threat on Monday. The building, including Ford's office, was searched, but police did not find any evidence to support the bomb threat.

"There is no evidence to support any threat to the public," a spokesperson for the Toronto police told reporters Monday afternoon.

He says an investigation into the incident has been launched.

The threat was first made public after Ford told reporters on Monday that an email was sent to his brother Sunday night.

"He has 12 hours to vacate otherwise city hall will blow. I have already set up explosive around," Ford read from a piece of paper that he said was a copy of the email.

Ford said he wasn't fazed by the threat but said that it was "very, very serious. I don't want people to panic."

Ford's spokeperson, Amin Massoudi, said an email was also sent to Deputy Mayor Norm Kelly.

"There was one email that came into Coun. (Doug) Ford's office and I understand one email that came into the deputy mayor's office," Massoudi said.

Asked if the emails were sent by the same person, Massoudi said he did not know.

CTV News has not seen the email and cannot confirm its contents.

After announcing the possible bomb threat to reporters, Ford also defended his decision to go public about the email.

"When I get something this serious sent to my brother's office and to the deputy mayor's office, it's only proper that the mayor of the city addresses this," he said.

According to Coun. Paula Fletcher, there is a protocol for dealing with these types of threats. She said that although the rules do not restrict officials from revealing the details of the threat, Fletcher said she hoped Ford knew that the bomb threat wasn't real before going public with the details of the email.

"I hope he's followed what I would call the good rules, or good common sense. And since we're still here in the building, I'm going to assume it was an angry letter from a disturbed individual."