This was contained in additional charges unsealed at a Chicago court, which is hearing the case against 49-year-old Headley, arrested by FBI in October along with another LeT operative and his school time friend Tahawwur Hussain Rana.

All other counts against Headley, a Chicago resident, carry a maximum of life imprisonment, except providing material support to the Denmark terror plot, which carries a maximum prison term of 15 years.

Headley was yesterday charged in a 12-count criminal information with six counts of conspiracy to bomb public places in India, murder and maim persons in India and Denmark, provide material support to foreign terrorist plots, provide material support to terror group Lashkar-e-Toiba, and six counts of aiding and abetting the murder of US citizens in India.

The charges were announced by Patrick J Fitzgerald, US Attorney for the Northern District of Illinois, and Robert D Grant, Special Agent-in-Charge of the Chicago Office of the Federal Bureau of Investigation.

Headley had made several trips to Mumbai between 2005 and 2008 taking video and pictures of the possible targets and took boat ride to identify the sea route for the terrorists, according to federal prosecutors.

The prosecutors said Headley also travelled to various other cities across India taking videos of several possible terrorist targets.

Headley, the FBI said, travelled to Mumbai for extended periods starting in September 2006, February 2007, September 2007, April 2008 and July 2008. Before leaving for India, each time he received instructions from co-conspirators to take video surveillance of locations in and around Mumbai.

During his stays in India, Headley conducted an extensive surveillance, taking pictures and making videotapes of various targets in India, including, but not limited to, the Taj Mahal hotel, Oberoi hotel, Leopold Cafe, Nariman House and the Chhatrapati Shivaji Terminus train station and other places of public use, State and Government facilities, public transport systems and infrastructure facilities, the FBI said.

Following each trip to India, Headley returned to Pakistan, the country of his birth, met other co-conspirators and provided results of his surveillance, including oral descriptions of various locations, the charge sheet said.

In March 2008, FBI said, Headley met co-conspirators and discussed potential landing sites for a team of attackers who would arrive by sea in Mumbai. He was instructed to take boat trips in and around the Mumbai harbour and surveillance video, which he did during his stay in India starting in April 2008.

The FBI said at various times, Headley conducted surveillances of other locations in Mumbai and elsewhere in India of facilities and locations that were not attacked in November 2008. Those included, but were not limited to, surveillance in March 2009 of the National Defence College in Delhi.