The 'general alert' was issued by the the Home Ministry, said officials. [Read more: After Mumbai airport, bomb threat in Chennai now]
Various divisions of the police like Bomb Detection and Disposal Squad, security division and sniffer dogs were rushed to service at major shopping malls like Ampa Skywalk, Spencer Plaza, Express Avenue, City Center and Alsa Mall, said the police.
"No suspicious objects were found and police advised people and traders on the need to be aware," they said.
Meanwhile, the Mumbai airport has also been put on high alert after warning from Intelligence Bureau (IB). [Read more: Terror from skies? Mumbai Airport on high alert]
The security around Chhatrapati Shivaji International Airport was tightened after there were reports of possible threat from an aircraft. The measures have been taken keeping in mind the third anniversary of Sept 13, 2008 Delhi bombings.
Reports suggest that terrorists may use small aircraft for the attacks in line with the Sept 9/11 attacks in America. Many sites are already under surveillance and the Delhi's Intelligence Bureau is specially being guarded after the reports.