Sony Pictures has cancelled the Christmas Day release of “The Interview,” after major theatre chains in the U.S. and Canada decided not to show the movie amid hackers’ threats of terrorist attacks.

After Cineplex, AMC, Regal Cinemas and Cinemarx announced they won’t be showing the comedy, Sony said it has decided “not to move forward with the planned Dec. 25 theatrical release.”

Federal investigators in the U.S. have now connected the Sony hacking to North Korea, an unnamed official told The Associated Press.

Earlier Wednesday, Cineplex said it would postpone showing “The Interview” in Canada in the wake of threats from a group of hackers calling themselves Guardians of Peace.

“After careful consideration of this unprecedented and complex situation, Cineplex Entertainment … will postpone presentation of the Sony Pictures movie, The Interview, ”the country’s largest theatre chain said in a statement.

“Cineplex takes seriously its commitment to the freedom of artistic expression, but we want to reassure our guests and staff that their safety and security is our number one priority. We look forward to a time when this situation is resolved and those responsible are apprehended.”

Seth Rogen and James Franco star in the movie as television journalists involved in a CIA plot to assassinate North Korean leader Kim Jong Un. The movie has been denounced in North Korea, which reportedly said that the film’s release would be an intolerable “act of war.”

In a threatening message, Guardians of Peace invoked 9/11 and warned people to stay away from places where the movie will be shown.

The FBI has said that it is aware of the threats and continues to investigate.

The same hackers breached Sony’s data files and released embarrassing emails between the studio’s executives, release schedules and corporate financial records, along with other sensitive information.

Asked about threats against theatres, the office of Public Safety Minister Steven Blaney said it does not comment on “specific or potential threats,” but added that the government is “always vigilant in monitoring any threats to Canada or Canadian interests.”

The office directed questions about movie theatre security to local enforcement officials.

With files from The Associated Press