Attribution of the 2008 Mumbai attacks were first made by the Indian authorities who said that the Mumbai attacks were directed by Lashkar-e-Taiba militants inside Pakistan. American intelligence agencies also agree with this attribution. Pakistan initially contested this attribution, but agreed this was the case on 7 January 2009. To back up its accusations, the Indian government supplied a dossier to Pakistan's high commission in Delhi. The Pakistan government dismissed the dossier as "not evidence," but also announced that it had detained over a hundred members of Jamaat-ud-Dawa, a charity linked with Lashkar-e-Taiba. In February 2009, Pakistan's Interior Minister Rehman Malik agreed that "some part of the conspiracy" did take place in Pakistan.
Moreover, Indian government officials have said that the attacks were so sophisticated that they must have had official backing from Pakistani "agencies", an accusation denied by Pakistan.
Attribution
The Mumbai attacks were planned and directed by Lashkar-e-Taiba militants inside Pakistan, and carried out by ten young armed men trained and sent to Mumbai and directed from inside Pakistan via mobile phones and VoIP.
In July 2009 Pakistani authorities confirmed to their Indian counterparts that their investigations confirmed that LeT plotted and financed the attacks. Investigations conducted in LeT camps in Karachi and Thatta revealed diaries, training manuals, maps of India and operational instructions. According to a report from Pakistani investigators to Indian authorities, "the investigation has established beyond any reasonable doubt that the defunct LeT activists conspired, abetted, planned, financed and established [the] communication network to carry out terror attacks in Mumbai."
The criminal investigation begun by the Mumbai police has identified 37 suspects – including two army officers – wanted for their alleged involvement in the plot. All but two of the suspects, many of whom are identified only through aliases, are Pakistani.
David Headley was a member of Lashkar-e-Taiba, and between 2002 and 2009 Headley travelled extensively as part of his work for LeT. Headey received training in small arms and countersurveillance from LeT, built a network of connections for the group, and was chief scout in scoping out targets for the Mumbai attacks.
Lashkar-e-Taiba was created and sponsored by Pakistan's intelligence agency, the Inter-Services Intelligence Directorate (ISI). US officials have stated that current or retired ISI officers probably played some role in the Mumbai attacks. An ISI officer known as Major Iqbal gave Headley $25,000 in cash in 2006 to scout out the target sites in Mumbai, helped him arrange a communications system for the attack, and oversaw a model of the Taj Mahal Hotel so that gunmen could know their way inside the target, according to Headley's testimony to Indian authorities. Headley also helped ISI recruit Indian agents to monitor Indian troop levels and movements, according to a US official. At the same time, Headley was also an informant for the US Drug Enforcement Administration, and Headley's wives warned American officials of Headley's involvement with LeT and his plotting of terrorist operations, warning specifically that the Taj Mahal Hotel may be their target.
Cooperation by Pakistan
Pakistan initially contested that Pakistanis were responsible for the attacks, but agreed this was the case on 7 January 2009.
A year after the attacks, Mumbai police continued to complain that Pakistani authorities are not co-operating by providing information for their investigation. Meanwhile, journalists in Pakistan said security agencies were preventing them from interviewing people from Kasab's village.
The Indian government supplied evidence to Pakistan's high commission in Delhi, in the form of interrogations, weapons, and call records of conversations during the attacks. The evidence, shown to friendly governments and media, provided a detailed sequence of training, supplying, and constant communications of attackers with handlers from Pakistan. In addition, Indian government officials said that the attacks were so sophisticated that they must have had official backing from Pakistani "agencies", an accusation denied by Pakistan.