The emails were received on Monday and Tuesday from a single mail id, police said.
More than 60 establishments in Mumbai, including the Brihanmumbai Municipal Corporation (BMC), prominent hospitals and colleges received emails threatening bomb blasts, following which searches were carried out although nothing suspicious was found in them, a police official said on Tuesday.
The emails were received on Monday and Tuesday from a single mail id, he said.
"The emails received on Tuesday were similar to those received on Monday, which said that there was a bomb threat to prominent private, state and civic-run hospitals and colleges across the city," he said.
As an investigation was underway, similar bomb threat emails were received by the BMC and other establishments, he said.
During the probe, the Mumbai police conducted security checks of those establishments and later it came to light that somebody played a mischief as nothing suspicious was found at all these places, he said.
Process to register a case against unidentified persons is underway at the Azad Maidan police station, he said.
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