Senior Indian officials are defending the government's security measures in Mumbai and promising answers, as they face popular anger and grief after three consecutive bomb blasts there killed at least 17 people and wounded 133 others.
Prime Minister Manmohan Singh arrived in the city Thursday, a day after the blasts exploded within 20 minutes of each other as commuters headed home from work.
Mr. Singh said authorities would continue to work together to “relentlessly” pursue those responsible.
So far, officials say police are investigating every possible “hostile” group, and that Indian intelligence had no warning before the bombings. No one has claimed responsibility, but authorities say they believe it was a “coordinated terror attack.”
Wednesday's attack is the worst to hit Mumbai since Pakistan-based militants laid siege to the city in 2008, killing 166 people.
A senior leader of the ruling Congress Party, Rahul Gandhi, defended the government's current security measures, saying it is impossible to provide completely airtight security.
Police believe Wednesday's blasts were caused by improvised explosive devices. They say that in two of the blasts, the bombs were attached to motor vehicles, while the third occurred on top of an electrical metering box above a billboard.
Home Secretary RK Singh said whoever launched the attack used ammonium nitrate — an ingredient for fertilizer — to make the IEDs. He said the explosive devices indicated “some sophistication.”
Shortly after the explosions, the Pakistani government condemned the violence.
U.S. President Barack Obama called the bombings “outrageous attacks” and pledged support to India's efforts to bring those responsible to justice.
U.N. Secretary-General Ban Ki-moon also offered condolences, saying nothing can justify “indiscriminate violence against civilians.”
Wednesday's attack also happened just two days after the fifth anniversary of a series of train bombings in Mumbai that killed more than 180 people. Indian authorities blamed that attack on Pakistani militants.
