MUMBAI: A thick smog cover diminished runway visibility to less than 500m at Mumbai airport on Sunday morning, forcing authorities to suspend operations for 45 minutes. “Operations were suspended from 8:30am to 9:15am,” a spokesperson for Mumbai International Airport Limited said.

There were no takeoffs or landings during this time and flights were diverted. It is unusual for such a phenomenon to occur in Mumbai during this time, though visibility does drop during heavy rains.

Five domestic flights were diverted to Ahmedabad: two each of Air Deccan and Jet Airways, and one of Indian. A GoAir flight from Chennai was diverted to Pune. But, according to unconfirmed reports, Pune airport was also shut for a while.

“Due to reduction in visibility, early morning flights were holding for 20-30 minutes,” said MG Junghare, GM (aerodrome), Mumbai region. “Apart from low visibility, another factor that affected operations was the runway lighting. Engineers were carrying out some work on the system.”

Junghare said the airport could have remained operational if full equipment support had been in place. Mumbai has the CAT-II instrumentation system, but it works only when runway visibility is about 550 metres.