Japan Airlines has announced that its system failure that began on Thursday morning has been resolved.

JAL says the failure was caused by a cyberattack. But it says no customer data was leaked, and no damage was caused by any virus. The company had suspended ticket sales, but they have now been resumed.

JAL says the attack began shortly before 7:30 on Thursday morning. The airline says the issue affected both domestic and international flights.

JAL says it deeply apologizes to customers and others for the inconvenience. It also says there is no impact on flight safety.

Officials said this could be a "DDoS attack," in which massive amounts of data are sent to make websites inaccessible.