IndiGo's Sharjah-Hyderabad flight was diverted to Karachi as a precaution on Sunday after pilots observed defect in one of the engines, officials of aviation regulator Directorate General of Civil Aviation (DGCA) said.
On July 14, IndiGo's Delhi-Vadodara flight was diverted to Jaipur out of precaution as vibrations were observed in the engines of the aircraft for a second.
The DGCA is investigating both the incidents, officials noted.
In a statement about Sunday's incident, IndiGo said its flight 6E-1406, operating from Sharjah to Hyderabad, was diverted to Karachi.
'The pilot observed a technical defect. Necessary procedures were followed and as a precaution, the aircraft was diverted to Karachi. An additional flight is being sent to Karachi to fly the passengers to Hyderabad,' it added.
The additional flight was sent from Ahmedabad, and it returned to Hyderabad during Sunday afternoon with all stranded passengers, sources said.
IndiGo's competitor SpiceJet is presently under regulatory scanner.
On July 6, the DGCA issued a show-cause notice to SpiceJet following at least eight incidents of technical malfunction in its aircraft since June 19.
One of the incidents happened on July 5 when SpiceJet's Delhi-Dubai flight was diverted to Karachi as the fuel indicator started malfunctioning.
The aviation regulator had on July 6 said SpiceJet had 'failed' to establish safe, efficient and reliable air services, and gave it three weeks to send a response to the notice.
An official of Pakistan Civil Aviation Authority (PCAA) confirmed that an IndiGo flight has landed at the Karachi airport.
'All the passengers have been taken care off properly and provided refreshments after they were moved to the transit lounge,' he said.
The PCAA official said the engineering crew had found faults in the engine number two of the IndiGo plane.
'The plane was not cleared for flight so the Indian carrier has sent an alternate aircraft,' he said.
The passengers will soon leave for Hyderabad, the PCAA official noted.
Last year, an IndiGo flight going from Sharjah to Luckow also had to make an emergency landing at the Karachi airport after a passenger fell ill mid-air and later expired.
