CHENNAI: Cyclone Arnab disrupted air traffic between Chennai and Andhra Pradesh, with 12 IndiGo flights connecting the city with Visakhapatnam, Vijayawada and Rajahmundry cancelled on Wednesday.The cancellations came as Cyclone Arnab, which formed over the Bay of Bengal, was expected to make landfall along the Andhra Pradesh coast.Six flights scheduled to depart from Chennai for the three Andhra Pradesh cities were cancelled. These included flights to Visakhapatnam scheduled for 5.25am, 10.30am and 4pm; flights to Vijayawada at 7am and 2.45pm; and a flight to Rajahmundry at 2.35pm.Six flights scheduled to arrive in Chennai from Visakhapatnam, Vijayawada and Rajahmundry were also cancelled as a precautionary measure amid the cyclone threat.The disruption affected passengers travelling in both directions between Chennai and the three cities. Airport sources said passengers had been alerted about the cancellations in advance and offered the option to reschedule their journeys free of cost.