New Delhi, Sept. 10 -- A technical failure in UK's air traffic control system forced the cancellation of more than 2,000 flights over two days, disrupting operations at 15 airports including Heathrow and stranding passengers on Indian carriers' London routes. Delays ran into a second day on Wednesday as airlines rebooked passengers and repositioned aircraft left at the wrong airports. On Wednesday, 291 flights - 120 departures and 171 arrivals - were cancelled at UK airports, about 5% of the 5,869 scheduled, aviation analytics company Cirium said. Cancellations on a normal day run between 1% and 2%. Tuesday was worse, with about 30.1% of 5,800 scheduled flights cancelled or not operated. Seven of the 24 flights scheduled from India to the U...