The AirAsia India plane, flying from the capital New Delhi to Srinagar, suffered a stalled engine and the captain told first officer Ravi Raj to send an emergency code to alert authorities about the situation.

Instead of the appropriate code 7700, Raj transmitted 7500 – the code for a hijacking – India’s Director General of Civil Aviation said in a statement on Friday.

Such a transmission is considered a major security alert across the world.

Precise details of the response from Indian authorities during the incident were not available, but local media reported last month that procedures for handling a hijacking were set in motion.

The Airbus A320 airliner safely landed later in the city of Chandigarh.

Raj was found guilty of “negligent conduct” and suspended for three months, the DGCA said, and the captain of the flight was also warned to be more vigilant.

AirAsia India, a joint venture between Malaysian low-cost giant AirAsia and India’s Tata Sons, told the Press Trust of India news agency that it had received the “final remarks on an event where a flight from Delhi to Srinagar diverted due to a technical issue”, but did not provide further details