Sources in the Home Ministry say the explosions in Dilsukhngar, which began just after 7 pm, appear to be a strike by "a well-trained" group which timed the explosions to cause the maximum damage.
The explosions took place at rush hour near the popular Konark cinema, an elevated bridge used by pedestrians, and a bus stand in Dilsukhnagar, which has a large fruit and vegetable market. The first explosion happened at 7.01 pm, the second five minutes later at 7.06 pm and the third a little later.
Officials were finding it tough to clear the packed area which has a maze of narrow lanes. Cellphone networks have been jammed in and around Dilsukhnagar to prevent false information from being disseminated.
Delhi and Mumbai have been put on high alert.
In 2007, twin blasts in the city killed 40 people.
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