David Coleman Headley and businessman Tahawwur Hussain Rana were named in a 12-count superseding indictment that for the first time alleged Rana was in on the planning of the attacks by a team of 10 terrorists.
Headley, 49, an American citizen, and Rana, 49, a Canadian national who has been in business in Chicago for more than a dozen years, are both in federal custody in Chicago.
Headley's attorney, John Theis, had no comment on the new indictment. A message was left for Rana's attorney, Patrick Blegan.
Retired Pakistani military officer Abdur Rehman Hashim Syed and reputed terrorist leader Ilyas Kashmiri — described as having been in regular contact with Al Qaeda's No. 3, Sheikh Mustafa Abu al-Yazid — also were charged in the new indictment.
The charges were the first for Kashmiri in the case that surfaced with the October arrest of Headley and Rana in Chicago. Syed previously had been charged with involvement in the plans to attack the Danish newspaper Jyllands Posten, which in 2005 printed 12 cartoons depicting the Prophet Muhammad that sparked outrage in the Muslim world.
Officials says all the defendants were linked to the terrorist organization Lashkar-e-Taiba, translated as Army of the Pure, which has long been involved in violent conflict with India over the disputed Kashmir territory. The Indian government has blamed the group for the Mumbai attacks.
The charges against Headley, formerly named Daood Gilani, are the same as those included by the government in a criminal information filed in federal court last fall. But the charges against Rana have been expanded to include participation in the Mumbai attacks.
Prosecutors have alleged that in a secretly recorded conversation in September 2009, Rana and Headley discussed the possible attack in Denmark as well as attacks on Bollywood, the Indian film industry; Somnath, a temple; and Shiv Sena, a political party with strains of Hindu nationalism.
They said Headley and Rana also spoke about a meeting between Rana and a man they called "Pasha" days before 10 gunmen rampaged through Mumbai. Prosecutors said Pasha is Syed. They said Syed helped put Headley in touch with Kashmiri, described as a leader of the terrorist group Harakat-ul Jihad Islami.