Delhi police on Tuesday arrested ex-Indian Air Force (IAF) personnel Ranjit Singh who was allegedly spying for Pakistan agency ISI. Ranjit Singh is an suspended IAF non-commissioned officer from Punjab. Ranjit was the seventh person to be arrested for having links with ISI. The intelligence agencies also issued warning of possible terror attack at the Parliament. With the fresh arrests, the ongoing spy ring in India has been busted. 'We were monitoring the activities of Airman Ranjit Singh. He was dismissed from service and handed over to police yesterday,' said Indian Air Force source..