A Jet Airways Boeing 737 on the runway as a man walks past at an airport in New Delhi. File picture: Adnan Abidi/Reuters

New Delhi - Thirty people fell sick on board an Indian passenger plane on Thursday after the pilots allegedly forgot to switch on an air pressurization system, local media reported.

The Jet Airways flight from Mumbai to Jaipur turned back after passengers experienced symptoms including bleeding from their ears and noses.

The pilots had forgotten to turn on a switch that controls a pressurization system during the flight's ascent, the PTI news agency reported, quoting an official from the Directorate General of Civil Aviation regulator.

The Ministry of Civil Aviation said in a tweet that 30 of the 166 people on board were affected and provided with medical treatment.