Over 30 people are feared killed and dozens injured as blasts rocked Delhi at three places on Saturday evening, Chief Minister Shiela Dikshit said.
She said the death toll could be higher.
The first explosion occurred in Paharganj market at 5:40 PM when it was crowded with people busy shopping for Diwali shopping, killing seven persons and injuring over 60 others.
Minutes later explosions rocked the Sarojini Nagar Market and Govindpuri area of Okhla in South Delhi.
Those injured in Paharganj were rushed to the Lady Hardinge, Safdarjang and Ram Manohar Lohia hospitals.
Police Commissioner K K Paul said that the explosive, which went off in Paharganj, was planted either in a motorcycle or a rickshaw.
Nine others were killed in Sarojini Nagar Market area and Govindpuri, police sources said.
Market areas of Paharganj and Sarojini Nagar were choc-a-bloc with shoppers doing their last minute purchases for Diwali next week.
Sixteen injured were admitted in the Ram Manohar Lohia hospital, of which four had succumbed to their injuries while others were being treated, Medical Superintendent N K Chaturvedi told PTI.
The blasts are suspected to be the handiwork of banned Pakistan-based Lashker-e-Toiba outfit.
An alert was sounded in the capital with the police chief asking people to be vigilant.
He said unclaimed objects lying anywhere should not be touched and information about these should be passed on to the police immediately.
The public has also been asked to inform the police about any suspicious persons moving in their neighbourhood in the recent days or any other suspicious movement they might have seen.
Preliminary reports said that just about an hour ago, police had received a call about a bomb placed in a bag in the Paharganj area. But before the police could get to the place, the explosive went off.