New Delhi/ Mumbai, June 09 (ANI): India beefed up security on its airports in metro cities on Monday after a group of heavily armed gunmen stormed the Jinnah International Airport in Karachi, where at least 26 people were killed in a night-long battle. Defence Expert Bharat Verma said the attack raises serious concerns for India. The assault took place on Sunday even as Prime Minister Nawaz Sharif's government tries to engage Taliban militants in talks to end years of fighting.