The hunt for the perpetrators of the triple bombing in Mumbai yesterday that killed 17 people and injured 131 has begun in earnest, Indian officials tell the Associated Press. Thus far, the Indian government has no leads and no one has claimed responsibility for the attacks. "We are not pointing a finger at this stage," Home Minister Palaniappan Chidambaram said. With wounds still fresh from the last major attack on two luxury hotels and a Jewish center in Mumbai in 2008, members of India's opposition party were more eager to assign blame. "Our message to Pakistan should be that you must dismantle the infrastructure for terrorism that you have created," said L.K. Advani, a senior leader of the Bharatiya Janata Party. Here are the clues and suspects Indian authorities and international observes are focusing on.

The clues "Ammonium nitrate had been used in the bombs," reports The New York Times. "Early evidence pointed to a timer rather than a remote trigger."  Speaking to the sophistication of the terrorists, home secretary R.K. Singh said "They were not crude bombs but sophisticated devices. Only somebody who has training can assemble those devices." Neelam Deo, director of the Mumbai-based think tank Gateway House, tells the Times it's not clear if the attacks were carried out by a foreign group but says the timing of the attack, so quickly after the assassination of Ahmed Wali Karzai, could provide a clue. “I am not sure that it’s a plot hatched with foreign connections,” she said. “What I think might be more the case that these guys had an agenda with some sort of timing in mind.” The AP reports that "surveillance cameras were in place at all three blast sites" but Indian officials have not revealed what they have revealed.

Suspects A senior American law enforcement official tells the Times that "early indications pointed to India-based militants, not to Lashkar-e-Taiba, a militant group in Pakistan." Lashkar-e-Taiba is the group suspected of carrying out the 2008 attacks on Mumbia. Writing in The Daily Beast, Brahma Chellaney, professor of strategic sutdies at the Center for Policy Research in New Delhi, blames Pakistan for the attack. Undercutting India’s strength by repeatedly targeting its economic capital is a geopolitical objective that only a state sponsor of terrorism can seek to pursue, not street gangs, underworld figures, or local fundamentalists, he writes. "And that sponsor—which made the mistake of leaving its marks on the three-day Mumbai terrorist siege in November 2008 that killed 166 people—is the Inter-Services Intelligence (ISI), Pakistan’s notorious military intelligence agency." However, Karl Inderfurth at the Center for Strategic and International Studies pushed back against that idea. "I cannot conceive of any instance Pakistan would have in instigating a crisis with India at this time," he says. "They're facing multiple crises at home they just had an outbreak of sectarian violence in Karachi. U.S.-Pakistan relations are at a new low. Just in two weeks time Pakistan and India will be meeting at the foreign ministers level. I can't imagine why Pakistan would have any reason to engage in any kind of provocation. So I think that we have to look elsewhere for where this attack came from. Let the evidence take the investigators where it will be but Pakistan has no interest in provoking a crisis with India." In his interview below at CSIS, Inderfurth attributes the attack to non-state actors, such as radical militant groups.