30 passengers were injured when shortly after takeoff, the flight crew forgot to select a switch to maintain cabin pressure and oxygen masks were deployed.
Citing initial information, the official said few passengers suffered nose bleeding.
Sustained low pressure can lead air to escape too forcefully and cause headaches, stomach pain and bleeding from the nose and ears.
As per their preliminary examination by ENT doctors, the five passengers suffered "barotrauma" of ear, which is caused due to a change in air pressure, said Rajendra Patankar, chief operating officer at the hospital.
The Aircraft Accident Investigation Bureau (AAIB) is conducting an enquiry into the incident, the statement said. The airline said it will arrange alternate flights for the passengers.
Nasal and ear bleeding of air passengers due to de-pressurisation of cabin is a rare occurrence, the two senior pilots who are working with two different airlines told PTI. Oxygen masks dropped and the plane returned to Mumbai.
The flight turned back around and landed back on the runway in Mumbai where eight passengers were taken to hospital.
Another passenger Satish Nair tweeted a picture of himself bleeding from the nose, and complained that "the safety of passengers had been completely ignored" by the airline.
The switch that works the crucial air-conditioning in the pressurised cabin is usually kept on.
Ministry of Civil Aviation has requested DGCAto file its report immediately on the issue.
"All guests were deplaned safely and taken to the terminal", the carrier said.
Adding further, he said, "The flight landed at Mumbai airport after an hour and we were told that we will be shifted to a different flight".
Passengers grab oxygen masks onboard the flight. Following the incident, Civil Aviation Minister Suresh Prabhu ordered a sweeping safety audit of every Indian airline, airport, training school, and fix company.