Indian carrier Kingfisher Airlines has canceled all operations following a strike by some of its employees, who say the privately owned carrier has not paid their salaries since March.

The airline has told civil aviation authorities that it will restart operations in the next few days, after it has settled this labor dispute. An airline spokesman says management will “review the situation on Oct. 4 or the day on which the strike is called off, whichever is earlier.” The airline has halted the sale of tickets until then, he adds.

Civil Aviation Minister Ajit Singh says the airline will remain grounded until authorities can approve and ascertain the airworthiness of Kingfisher’s aircraft.

“Passenger safety cannot be compromised,” Singh says. If there is a safety issue with Kingfisher, we will close it down.”

The Directorate General of Civil Aviation (DGCA) separately says it is “very concerned about the situation” and that it is ready to talk to Kingfisher employees if they are not satisfied with the airline’s plan.

Kingfisher CEO Sanjay Aggarwal, who met the DGCA, meanwhile, says the company will “try and clear salaries in next four weeks.”