MUMBAI (Reuters) - Indian intelligence agencies received no warnings before the three bomb blasts that killed 18 people in Mumbai, the biggest attack since Pakistani-based militants rampaged through the financial hub in 2008, a top official said on Thursday.
Suspicion however fell on the Indian Mujahideen, a shadowy home-grown militant group known for its city-to-city bombing campaigns using small explosive devices planted in restaurants, at bus stops and on busy streets.
"There was no intelligence regarding a militant attack in Mumbai. That is not a failure of intelligence agencies," Home Minister Palaniappan Chidambaram told a news conference.
"Know that perpetrators have attacked and have worked in a very very clandestine manner. Maybe it's a very small group, maybe they did not communicate with each other."
He said it was too early to point the finger at a particular group, but said the "coordinated terror attacks" could be in retaliation to a number of plots recently stopped by police or the arrests, including from the Indian Mujahideen.
The Indian Mujahideen have been accused of having ties with Pakistani militant groups fighting Indian rule in Kashmir.
The bombings were the biggest militant attack on Mumbai since the 2008 assaults killed 166 people, raised tensions with neighbor and nuclear rival Pakistan, and left a city on edge.
The blasts come as India and Pakistan seek to normalize ties. Pakistani leaders were swift in condemning the bombings, as was President Barack Obama. Top U.S. diplomat Hillary Clinton is due in India for scheduled talks next week.
There was no immediate indication any Pakistani group was involved. But any suggestion of attributing blame to Islamabad would complicate a fraught relationship with India -- with whom it has a long-running dispute over Kashmir -- and further unravel ties with the United States.
"We live in the most troubled neighborhood in the world. Pakistan and Afghanistan are the epicenter of terrorism," said Chidambaram, adding that Pakistan had still not given India support in going after those behind the 2008 attacks in Mumbai.
HOME GROWN GROUPS? There was no immediate claim of responsibility for the bombs, which were mixed with ammonium nitrate, a chemical compound often used in improvised explosive devices (IEDs).
"It's very likely coordinated by Indian Mujahideen looking at the severity and scale of the attacks -- in the past they've used tiffin carrier bombs and IEDs," said Dr Rohan Gunaratna, a Singapore-based al Qaeda expert.
"Certainly there can be links between those who have done these attacks and overseas sources but the attacks themselves have been conducted by local groups, home grown Indian groups."
Chidambaram said 18 people had died in the attacks, lowering an earlier figure of 21. He said 23 out of the 131 injured and admitted to hospitals were in a critical state.
Newspaper headlines voiced a mix of resignation and outrage over the latest attacks on a coastal city of more than 10 million that is home to India's main stock exchanges.
"Attacked. Again," said the Hindustan Times. "We're All Sitting Ducks," said the Economic Times.
The blasts came as beleaguered Prime Minister Manmohan Singh struggles to get past a series of corruption scandals and a resurgent opposition that has led to policy paralysis in Asia's third largest economy. A cabinet reshuffle this week was criticized as too little, too late.
Mumbai has a long history of deadly bombings and Wednesday's attacks did not rattle financial markets. The home minister said the attacks were not aimed at markets.
JEWELRY MARKETS TARGETED The bombings were centered mainly on south Mumbai's jewelry market area, crowded with diamond and precious metals traders and artisans. It was not the first time it was attacked.
The blasts occurred at about 6.45 pm (1315 GMT) on Wednesday within minutes of each other. One bomb was placed at the side of the road, another on a motorbike and a third on the roof of a bus stop.
The home minister said the bombs were detonated with timers, a clock or other triggers, but not done remotely.
The biggest blast was in the Opera House area, a crowded hub for diamond traders. Pakistani-based militants carried out the bloody rampage in 2008 near the same popular area.
Another blast, also in south Mumbai, was at the Zaveri Bazaar, India's largest bullion market which was hit twice in the past.
The third blast was at Dadar, in a street housing Muslim and Hindu shops in the center of the coastal city.
(Writing by Paul de Bendern, additional reporting by James Pomfret in New Delhi, Rosemary Arackambil and Rajendra Jadhav in Mumbai; Editing by Krittivas Mukherjee and Daniel Magnowski)
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