RavnAir, an airline that services local communities in Alaska, was hit by a “malicious cyber attack” on Saturday, canceling at least half-a-dozen flights and affecting 260 passengers. All flights using the company’s Dash 8 aircraft had been canceled.

“While we continue to work with the FBI, other authorities, and a cyber security company, to restore affected systems, we are proactively cancelling all RavnAir Alaska Dash 8 flights until 12 noon today, and we expect to experience other schedule cancellations and delays within the RavnAir Alaska (Dash 8 Aircraft) network throughout the rest of the day because the cyber attack forced us to disconnect our Dash 8 maintenance system and its back-up,” RavnAir said in a written statement.

It’s still unclear where the cyberattack came from. The company is trying to reschedule passengers on other flights if possible.

Airlines are often prime targets for cyberattacks, as they collect massive amounts of valuable information such as credit card and passport information on passengers. A 2015 PricewaterhouseCoopers survey of airline CEOs found that 85% of respondents view cybersecurity as a significant risk.

British Airways and Cathay Pacific are just two of the major airlines that have been targeted by cyberattacks in recent years.

Netscout, a provider of application and network performance products, found that cyberattacks on passenger air travel increased by 15,000% between 2017 and 2018.