An IndiGo plane from the national capital to Doha was diverted to Karachi airport on Sunday night after a passenger fell ill onboard and was later declared dead on arrival, according to officials.

Abdullah, a Nigerian national who was around 60 years old, was declared dead on arrival, the officials said.

The officials said the aircraft A320-271N, which was parked at Karachi airport for nearly five hours, returned to Delhi after the authorities in Karachi issued the death certificate of the passenger and all formalities were completed.

An IndiGo spokesperson on Monday said the flight 6E-1736, operating from Delhi to Doha (Qatar), was diverted to Karachi (Pakistan) due to a medical emergency on board.

"Unfortunately, on arrival, the passenger was declared dead by the airport medical team," the spokesperson said in a statement.

Civil Aviation Authority officials at Karachi said the passenger fell ill onboard and the captain requested for an emergency landing at Jinnah International Airport in Karachi.

Doctors from the health department were sent to provide treatment but the passenger had passed away. After the death certificate of the passenger was issued and all formalities were completed, the plane returned to Delhi.

"We are deeply saddened by the news and our prayers and wishes are with his family and loved ones," the airline spokesperson said.

The total number of people onboard the aircraft could not be immediately ascertained.