New Delhi | No airline, however large, will be permitted to cause hardship to passengers through planning failures and non-compliance with regulations, Civil Aviation Minister Ram Mohan Naidu said on Tuesday on the mass disruptions in IndiGo flight schedules.

Making a statement in the Lok Sabha, Naidu said "strict and appropriate action will be taken" against IndiGo for the flight disruptions that have affected passengers across the country.

The minister said the Directorate General of Civil Aviation (DGCA) has already issued notices to IndiGo and that the airline is being held fully accountable for the chaos caused by its internal crew-rostering failures.

Naidu said IndiGo flight schedules are stabilising and all other airlines continue to operate smoothly across the country.

"IndiGo was ordered to issue refunds promptly and more than Rs 750 crore has already reached passengers," the minister said.

He said airports across the country are reporting normal conditions, with no crowding or distress.

"Refunds, baggage tracing and passenger support measures remain under the supervision of the ministry. Directorate General of Civil Aviation has issued show-cause notices to IndiGo's senior leadership and commenced a detailed enforcement investigation," Naidu said.

"Based on the report, strict and appropriate action will be taken," he said.

Naidu said the government is determined to build a robust and competitive aviation ecosystem.

"Through our policies, we are encouraging more new airlines to start and operate in India," he said.

"Safety in civil aviation is completely non-negotiable," he added.

Expressing dissatisfaction over the minister's statement, opposition parties staged a walkout in the Lok Sabha.