Although no group claimed responsibility, the explosions hit locations where a terror siege nearly three years ago killed 166 people. Wednesday also coincided with the birthday of the lone surviving gunman of the 2008 attack.The November 2008 attacks targeted a pair of landmark luxury hotels, a train station, a hospital and a Chabad house. According to diplomatic cables released via wikileaks, and testimony from a Chicago trial of a US citizen accused of scouting locations for the Mumbai attack, Pakistan's Inter-Services Intelligence directorate (ISI) provided training and support to Lashkar-e-Taiba members prior to the Mumbai attacks.
Arup Patnaik, a top police officer, said the attackers used improvised explosive devices in the attack, hidden in an umbrella in the Jhaveri Bazaar jewelry market and kept in a car in the business district of Opera House.
Indian officials say they believe the responsibility of Wednesday's attack rests with the Indian Mujahideen, a group that works closely with Lashkar-e-Taiba.
Lashkar-e-Taiba is the group suspected to be behind the 2008 attack.
All three blasts happened from 6:50 p.m. to 7 p.m., when all the neighborhoods would have been packed with office workers and commuters.
The blasts hit the crowded Dadar neighborhood at rush hour, the famed jewelry market Jhaveri Bazaar and the busy business district of Opera House, an official at the city's Police Control Room said. The official spoke on condition of anonymity because of office policy.
The explosions happened around 7 p.m., when all the neighborhoods would have been packed with office workers and commuters.
Authorities say an early indicator of a terror strike was the close timing of the string of explosions.
Indian authorities have not yet identified any suspects, although the locations of the targets and the timing of the blasts to coincide with the lone surviving Mumbai gunman's birthday hardly seem coincidental.
India's Home Affairs Minister Palaniappan Chidambaram confirmed that the explosive devices were made from ammonium nitrate and investigators believe that the devices weren't set off remotely.