The main runway of the international airport in Mumbai remained shut this morning as incessant rains hampered towing away of a Turkish Airline plane stuck in mud near the taxiway.Officials said continuous rain in the airport area has made the ground near the main runway more slushy, preventing movement of equipment for towing away the stranded plane.According to a Mumbai International Airport Ltd (MIAL) spokesperson, the arrival and departure of flights from the second runway is getting delayed by around 30 minutes.