Red alert has been sounded in the capital after serial blasts rocked three places, in which at least 16 people were killed and 60 injured.
Delhi Police has sealed the borders and beefed up the security in the capital.
The first blast occurred at Paharganj, nearly 300 meters from the New Delhi Railway station at 1725 hrs.
Panic gripped at the platforms as many trains were scheduled to depart from the station.
The other blasts took place at Sarojini Nagar and Govindpuri in South Delhi.
The police also recovered a bomb from a bank in the Chandni Chowk area, which was defused by the bomb squad immediately.
Delhi Metro Spokesman said the security at the metro had been tightened and the security staff had been alerted to keep an eye on suspicious movements by any person in the metro tunnel.
However, the metro was running its services as usual, the spokesman said.
An eyewitness at Paharganj said the bomb had been planted at the busy intersection where many people pass by in the peak hours.
A computer engineer, who was passing by the area, was seriously injured in the blast and taken to the nearby hospital for treatment, another eyewitness said.
The blast at Paharganj was so powerful that it shattered the glass panes of the nearby buildings.
Meanwhile, red alert has also been issued in neighbouring Haryana and Uttar Pradesh besides Gujarat and Karnataka.