People flying in and out of the city could be stranded at long queues on ground and on air as the Mumbai airport's main runway would be shut for eight hours on Tuesday and Wednesday.
The ongoing widening work on the Mithi river flowing beneath the airstrip resulted the closure.
A Mumbai International Airport Limited (MIAL) spokesperson confirmed the move.
"The closure was necessary for removal of the blast fence at the beginning of the main runway," said a MIAL spokesperson.
The secondary lacks equipments necessary for low visibility operations.