The victim, named as Bonnie Witherall, worked as a nurse in the building - she was found with at least one bullet to the head.

BBC: Colleagues of Bonnie Weatherall

Uday Banerjee, the head of India's Central Industrial Security Force, told reporters at the airport that something sounding like gunshots was heard, but no one saw anything and no bullet casings were found.

CNN: New Delhi airport gets security scare