New Delhi, April 11 -- The White House on Thursday called the extradition of a key conspirator in the 26/11 Mumbai terror attacks, Tahawwur Rana, to India as a "critical step toward seeking justice" for the six Americans and numerous victims who lost their lives in the "heinous attacks".

Tahawwur Rana, 64, a Canadian citizen of Pakistani origin, was formally arrested by the National Investigation Agency (NIA) after he was extradited from the United States on Thursday evening after a long and protractive legal battle. The NIA secured an 18-day remand to continue its investigation into his role in the attacks, which killed 166 people in 2008 in Mumbai.

Following the extradition, the US State Department spokesperson Tammy Bruce said Rana i...