The Bengal government has sought a report from the Directorate General of Civil Aviation (DGCA) to know if prior permission was taken to follow the route on which chief minister Mamata Banerjee’s aircraft was flying to Calcutta from Varanasi on Friday.

The plane carrying the chief minister from Varanasi to Calcutta had to lose height suddenly after it was caught in a turbulence on Friday. Owing to the impact of the steep climb-down, Mamata had suffered a waist injury.

Sources said that the authorities of the civil aviation ministry have started a probe into the matter after the state government sought the report.

Mamata took the flight from Varanasi around 2.28pm on Friday.

and was accompanied by her security personnel. Lata Banerjee, the mother of Trinamul's national general secretary and MP Abhishek Banerjee was also aboard.

About a few minutes before landing, the plane was caught in a mid-air turbulence around 50 km northwest of Calcutta. The air traffic control was contacted by the pilot, and was asked to come down from 7000ft to 2000ft--a descent of 5000ft. This sudden jerk took the passengers by surprise and is said to have injured Mamata in the waist as well.

The incident assumed political overtones, as an article in Saturday’s Jaago Bangla — the Trinamul Congress mouthpiece-— questioned the frequency of such turbulent plane rides whenever Mamata happened to be on board.

“The flight was caught in mid-air turbulence around 50km northwest of Calcutta,” an airport official said on Friday. The pilot of the Falcon aircraft, hired by the state government for the chief minister, had contacted air traffic control when the turbulence started, the official said. “The ATC directed the pilot to go for a climb-down from 7,000ft to 2,000ft,” he said.