The bombings came with markets crowded just days before a Muslim and a Hindu celebration.
An obscure Kashmiri militant group has claimed responsibility for the three blasts.
Police have not commented on who may have carried out the attacks but they say their investigation is making progress, and a number of people have been taken in for questioning.
Joining other world leaders, U.S. President George W. Bush on 30 October condemned the New Delhi bombings and expressed sympathy for the victims.
(compiled from wire reports)