The Guardian newspaper Media Group was hit by a serious IT incident, which is believed to be a ransomware attack.

The incident began late on Tuesday night and has affected parts of the company’s technology infrastructure, forcing staff to work from home.

chief executive, Anna Bateson, and the editor-in-chief, Katharine Viner, told staff: “As everyone knows, there has been a serious incident which has affected our IT network and systems in the last 24 hours. We believe this to be a ransomware attack but are continuing to consider all possibilities.

“We are continuing to publish globally to our website and apps and although some of our internal systems are affected, we are confident we will be able to publish in print tomorrow. Our technology teams have been working to deal with all aspects of this incident, with the vast majority of our staff able to work from home as we did during the pandemic.

“We will continue to keep our staff and anyone else affected informed. We will update everyone again at the end of the day. With a few key exceptions we would like everyone to work from home for the remainder of the week unless we notify you otherwise.

“Thank you to everyone working hard throughout this incident to keep us publishing, looking after our readers, supporters and advertisers, and to keep our core systems available for colleagues.”

The company has not said what ransom, if any, has been demanded by hackers.