New Delhi – Fifty flights diverted to other airports and 150 flights were delayed due to dense fog and poor visibility at the Indira Gandhi International Airport. With the visibility dipping to 50 metres, no flights could take-off from Delhi in the morning for nearly four hours.Dense fog condition is likely to continue over Uttar Pradesh and Bihar and some parts of Haryana, Punjab and West Bengal in the next two to three days announced by India Meteorological department.