Japan Airlines operations were disrupted by a cyberattack on Thursday, causing delays to both domestic and international flights.

The airline said in a statement that it had stopped booking any more tickets for flights departing on Thursday. Its mobile app was temporarily disabled.

At 7:24 a.m., Japan Airlines, known as JAL, identified a problem with equipment connecting the company’s internal systems to external networks. About 90 minutes later, JAL temporarily shut down the router device responsible for the problems.

More than 40 flights were delayed at various airports across Japan as of around noon on Thursday, according to the public broadcaster NHK.

While the full extent of the disruption was still being investigated, JAL was working to restore operations as quickly as possible. The airline added that there was no impact on the safety of its flights and no flights had been canceled as of around noon on Thursday.