Who's Behind the India Bombings?

Even as the dead are still being counted in India's worst terrorist attack in more than a decade, suspicion has already fallen on Islamic terrorists — though not al-Qaeda. India is home to a Muslim insurgency in Kashmir, and earlier in the day militants killed eight people and injured 30 in five separate bomb attacks in the capital, Srinagar. And while no one said those same insurgents carried out Tuesday's rush-hour train attacks in Bombay — which police said killed at least 130 people and injured 260 — security sources told TIME they suspected a shadowy alliance of the Pakistan-based Lashkar-e-Toiba (LeT) working with indigenous Indian Muslims from the banned Student Islamic Movemement of India (SIMI).

SIMI detonated a total of nine bombs in Bombay during the course of 2003, killing close to 80 people and injuring hundreds more. The same loose grouping of Islamic radicals are also suspected of being behind a series of attacks in India in the last year that included three blasts in New Delhi last October that killed 60 and three more in the holy Hindu city of Varanasi in March this year, which killed 20, as well as smaller attacks in Bangalore and Hyderabad.

Ajay Sahni of the Institute for Conflict Management in New Delhi said it was unlikely that there had been any trigger for the attacks. Rather this was an "ongoing war" against Hindu-majority India by South Asian Muslims. "It is a continuous process of preparing for attacks and carrying them out," he said. "When these people are able to bring something to fruition, they do it. The act itself is the objective. It says: 'We're here. And this is what we are going to do to you.'" In a paper published Monday, Institute research fellow Bibhu Prasad Routray warned that SIMI had been stepping up its operations in Bombay and the surrounding state of Maharashtra. He described several "SIMI strongholds" in the state, adding that the "seizure of 30 kilograms of RDX, 17 AK-47s and 50 hand grenades from Aurangabad and Malegaon [two Maharashtran towns] between May 9 and 12 and subsequent arrests of 11 LeT terrorists pointed to linkages between SIMI and the LeT."

India is home to the second largest Muslim population in the world, around 150 million people. But in a nation of more than a billion people, Muslims are often a disadvantaged minority. In the eyes of many Hindus, no Muslim can ever truly belong in India. The origins of this antagonism are centuries old. In essence, hardline Hindus regard as a national humiliation the Islamic influence that pervades India's history, starting with the Mughal Renaissance in the 16th century, continuing with the birth of Islamic fundamentalism in Asia in northern India in the 1860s (the same creed followed by the Taliban) and enduring even today in India's national symbol, the Mughal mausoleum of the Taj Mahal. This distrust of Islam has only increased since independence in 1947: modern India was founded in the Muslim-Hindu bloodletting of Partition from Pakistan, in which a million people died, and since then three wars against Islamic neighbor Pakistan have killed millions more.

Today, much of this tension stems from India's rule over Muslim-dominated Kashmir in the face of strident Pakistani opposition. The war on terror and the 1998-2004 rule of the Bharatiya Janata Party (BJP) on a Hindu nationalist agenda — which also stoked a Hindu pogrom in Gujarat in 2002 in which 2,000 Muslims died — has lent further legitimacy to India's lurking anti-Muslim prejudice. In 2003, just before twin bomb blasts in August that killed more than 50, TIME spoke to "Umar," a SIMI operative, or Ansar ("guide"), who said his men were carrying out the attacks. The 44-year-old said: "This country doesn't work for Muslims any more. You can't get a proper education, you can't get a job. You're not even safe." He said he and his men had no intention of ever ending their murderous campaign. "We will continue," he told TIME. "There is no limits on our actions... Even to kill children is good — you stop the generation there, at the beginning."

The numbers in Tuesday's attacks are likely to rise. All the bombs were detonated between 6 p.m. and 7 p.m. on the Western line, which runs from Bombay's central station, Churchgate, through which a million commuters pass every day. Typically, a Bombay train carries around 4,500 people — three times its official capacity — and at rush hour, each carriage would have been stuffed, with passengers hanging onto doors and sitting on roofs. For terrorists looking to maximize carnage, it was an all too tempting target.