A Guwahati-bound IndiGo flight from Mumbai had to be diverted to Dhaka early Saturday after thick fog obstructed midnight landing attempts, first in Guwahati and then in Kolkata, officials said. The diversion led to a delay of nearly 12 hours, six of which were spent by the 178 passengers inside the plane at the Dhaka airport. The flight (6E-5319) touched down in Dhaka at 4 am. It was initially scheduled to land in Guwahati at 12:15 am on Saturday but did so only after 11 am.