A bomb threat on Wednesday sent alarm bells ringing in the North Block, which houses the home ministry office, but was declared a hoax after nothing objectionable was found, officials said.
The threat was received through an email around 3.30 pm by a senior officer posted at the ministry, according to a Delhi Fire Services official.
It was written in the email that the "building will explode as bomb is planted", a police officer said and added that the IP address and other details of the mail are being checked.
The police and fire department personnel, a dog squad, and bomb disposal and detection teams were deployed for the search operation at the North Block.
Fire official Prem Lal said two fire tenders were also there.
The Delhi police after conducting a thorough search of the building announced the bomb threat to be a hoax.
"A thorough search has been carried out in the entire building and nothing suspicious has been found. Security agencies have come to the conclusion that the mail was a hoax," a source in the home ministry said.
In the past few weeks, bomb threat emails have been received by many establishments in the national capital, including schools and hospitals.
Delhi's Chacha Nehru Hospital received a bomb threat on April 30 while more than 150 schools got threats from a Russia-based mailing service company on May 1.
Twenty hospitals, the IGI Airport and the Northern Railways' CPRO office in Delhi received bomb threats through emails from a Cyprus-based mailing service company on May 12.
Seven Delhi hospitals and the Tihar Jail received bomb threats from the same Cyprus-based mailing service company on May 14.
The Delhi Police is conducting investigations into the email bomb threats.
