A federal grand jury has added Pakistan born Canadian terror suspect Tahawwur Hussain Rana to charges filed against David Coleman Headley, accusing them of laying the groundwork for the November 2008 Mumbai terrorist attacks.

Pakistani-American Headley had already been charged on December 7 in connection with the Mumbai attacks, but the 12-count superseding indictment unsealed here on Thursday also added Rana as an alleged conspirator in planning the bloody rampage.