Even as the first suspects in the Mumbai bombings were named yesterday, India was facing the possibility that Tuesday's attacks were committed, at least in part, by its own citizens.
Police released photographs of the first two suspects, named as Sayyad Zabiuddin and Zulfeqar Fayyaz. Their nationalities were not given, but Indian intelligence sources say they suspect the seven co-ordinated bombings were a joint operation by Pakistan-based militants and an entirely Indian organisation, the Students' Islamic Movement of India (Simi).
Just as Londoners a year ago faced the shock of learning that the 7 July bombers were British, Indians may have to deal with the realisation that the Mumbai attacks were partly the work of an enemy within, an Indian militant group which has openly declared jihad against secular India.
More than 350 people were detained for questioning in raids across Mumbai. But the raids appeared to be a very loose operation, with most of those detained released without charge after a few hours.
Indian intelligence is investigating the possibility that the bombings were committed out by Simi and Lashkar-e Toiba. Both organisations have issued denials and condemned the bombings.
"So far, it looks like there was a substantial involvement of Lashkar-e-Toiba with local support," D K Shankaran, the most senior bureaucrat in Maharashtra state, said. But it may be the suspicions surrounding the home-grown Simi that will prove more disturbing for India.
Founded in 1977 in Uttar Pradesh, Simi has declared jihad against secular India, with the avowed aim of converting the entire country to Islam. The group has repeatedly praised Osama bin Laden as a Muslim hero, and has been banned in India since 2002.
India's Supreme Court rejected a plea for the ban on the group to be overturned just five days before the bombings. The group recruits entirely from inside India. Although it is nominally a students' movement, it accepts members up to the age of 30.
There may be political reasons for the Indian intelligence establishment to point towards Simi. In what is widely seen as an attempt to court Muslim votes, the Chief Minister of Uttar Pradesh, Mulayam Singh Yadav, has been pushing for the ban on the group to be lifted. Yesterday he insisted Simi is "not a terrorist organisation".
But Simi has been linked to militant attacks in Mumbai. In 2003, police named Simi and Lashkar as suspects in a smaller bombing on the city's train network, and the same year six Simi activists were arrested with lethal chemicals, arms and ammunition in their possession.
A senior officer in Malvandipolice station, from which some of the city-wide raids were launched, said they were a general dragnet to pick up anyone suspicious, and most of the 141 detained at Malvandi had been released without charge. This sort of "round up the usual suspects" tactic is commonly used by police in India after major incidents.
Lashkar, the other group at the centre of suspicions, has long been acknowledged as having the most dangerous militants operating in Kashmir. Often wrongly described as a Kashmiri group, it is based in Pakistan and most of its membership is recruited there, a fact not lost on India, which demanded Pakistan "dismantle the infrastructure of terrorism" on its territory in the wake of the bombings.
Lashkar used to be closely linked to Pakistan's ISI intelligence, but the Pakistani establishment says those links have been severed.
Pakistan's Foreign Minister, Khurshid Kasuri, reacted angrily to Indian criticism, saying: "You can't really blame everything on Pakistan; it's very unfair." A man claiming to represent al-Qa'ida has phoned a news agency in Kashmir claiming the organisation has established a presence in India for the first time. He did not claim responsibility for the Bombay bombings, but called on Muslims in India to "adopt a path of freedom and jihad". The name he gave for his group, al-Qa'ida Jammu and Kashmir, appears to be a deliberate echo of Abu Musab al-Zarqawi's al-Qa'ida in Iraq. He named the leader of the new group as Abu Adbul Rehman Ansari.Reuse content