Reported By Tanima Biswas And Sudhi Ranjan Sen Edited By Sanchari Bhattacharya

From the moment Air Force One, US President Barack Obama's special aircraft, enters Indian airspace, a set of unprecedented security measures will be activated. He will land in Delhi on Sunday on a three-day visit during which he will be the chief guest at the Republic Day celebrations.

The Delhi Police has filed a murder case in the death of Sunanda Pushkar, wife of Congress lawmaker and Shashi Tharoor. Mr Tharoor has said he is "stunned" and has assured the police of his "full co-operation."

From the moment Air Force One, US President Barack Obama's special aircraft, enters Indian airspace, a set of unprecedented security measures will be activated. He will land in Delhi on Sunday on a three-day visit during which he will be the chief guest at the Republic Day celebrations.

The Delhi Police has filed a murder case in the death of Sunanda Pushkar, wife of Congress lawmaker and Shashi Tharoor. Mr Tharoor has said he is "stunned" and has assured the police of his "full co-operation."