An Air India aircraft narrowly avoided colliding with a Vistara plane over Mumbai on Wednesday, PTI reported on Monday. Vistara’s UK 997 flight from Delhi to Pune, with 152 passengers on board, was just 100 ft from Air India’s Bengaluru-bound AI 631 flight with 109 on board when the pilot steered it away.

The Aircraft Accident Investigation Bureau has ordered an inquiry into the incident. The air traffic controllers who handled the two flights have been suspended, according to The Times of India. Vistara has also taken the two pilots operating the aircraft off duty.

An unidentified official told the daily that the Vistara aircraft had descended from 29,000 ft to 27,100 ft as the Air India flight approached it from the opposite direction. “[Air India Captain Anupama Kohli] could see the Vistara flight approaching and hear the air traffic controllers asking UK 997 why it was on this level,” the official said. The Vistara pilot told the controllers that it had asked the flight to descend to that level.

“[Captain Kohli] saw the Vistara plane closing in from her left side towards her,” the official added. “Then, as per a Resolution Advisory in the cockpit, Kohli immediately climbed and turned right to steer clear from the Vistara plane.”

The two flights ended up 600 ft clear of each other, thus averting a disaster, The Times of India reported.

Vistara officials told PTI that their pilots had followed the standard operating procedure during the crisis and had carried out an “uneventful landing”. However, Air India officials said the near-collision was the result of an argument between the Vistara pilots and the air traffic controller. They praised Captain Kohli’s “timely action” and said the Aircraft Accident Investigation Bureau had cleared her for flying.