Oct. 19—Some operations at Fresno’s FOX television affiliate, KMPH Channel 26, and its parent company Sinclair Broadcast Group have been disrupted by a ransomware attack on their computer systems.

Justin Willis, an anchor for the station’s Great Day morning show, took to Facebook on Tuesday to explain that the weekend attack by hackers at the station and at Sinclair “left us unable to log into our systems that allow us to produce our newscasts as we normally would.”

On Facebook and on Twitter, the station acknowledged Monday that systems at Sinclair had been hacked, reporting that “certain servers and workstations in its environment were encrypted with ransomware and that certain office and operational networks were disrupted.”

Also on Monday, in a press release and in a filing with the U.S. Securities and Exchange Commission, Sinclair reported that the hack “has caused — and may continue to cause — disruption to parts of the company’s business,” including service to its advertisers.

The company’s statement added that “data was also taken from the company’s network.”

Telephone calls from The Bee could not be completed to either the KMPH studio in Fresno or to Sinclair’s headquarters in Maryland as the company’s phone systems were down.

The station reported Tuesday that all Sinclair stations were operational, but that “certain features, such as online live streams, have been interrupted.”

Cybersecurity firm Recorded Future, in its online publication The Record, reported Sunday that the attack “took down the Sinclair internal corporate network, email servers, phone services, and the broadcasting systems of local TV stations.”

Citing multiple sources, The Record reported that “as a result of the attack, many channels weren’t able to broadcast morning shows, news segments, and scheduled NFL games, according to a barrage of tweets coming from viewers and the TV channels themselves.”

The Fresno station’s social media posts and the company’s statements came after Sinclair said it had identified “a potential security incident” on Saturday. On Sunday, it determined that some of its systems were affected by ransomware.

In early July, Sinclair alerted its stations of “a serious…