A formerly unknown group that calls itself the Deccan Mujahideen has claimed responsibility for the attacks. However, some authorities believe that it is a front group for another organization. The Indian government believes that a terrorist group from Pakistan, possibly affiliated with Pakistani militant groups Lashkar-e-Taiba and Jaish-e-Mohammed, both of which have ties to Al Qaeda, may be responsible.
India and the United States have both pressured the government of Pakistan to cooperate with a thorough investigation into the matter. Pakistan has responded that it will look into the role of "nonstable actors" in plotting the attacks.

The first attack occurred about 9:30 pm at the Cafe Leopold on November 26, 2008. A man was seen firing an AK-47 in the Taj Mahal Palace hotel lobby before fleeing into the kitchen. Another series of injuries was reported when a gunman opened fire at a central train station.
As the rampage progressed, gunmen opened fire at several locations throughout the city, including a crowded train station, a popular restaurant and several luxury hotels. The terrorists apparently sought victims with British or American passports.