A senior police official said top officials were reviewing the security situation in the city.
"A tight security apparatus has been put in place. Senior officials are on the streets monitoring the security scenario. Police personnel have been deployed across the city," a senior police official said.
The official said police personnel were deployed at public places like malls, cinema halls, parks, popular hangouts, ISBT and railway station. They are conducting checkings.
Three explosions were reported from south Mumbai's Zaveri Bazar, Dadar in Central Mumbai and Opera House in Charni Road following which this action has been taken, the official said.
The national capital last month had a minor scare when a low intensity blast took place outside Delhi High Court. No one was injured in the incident.
"There is nothing to worry. All precautions have been taken. We appeal to the citizens to report to us about any suspicious objects or persons they come across," the official said.