The hackers, who called themselves “Guardians of Peace,” threatened people not to go see Sony Pictures' new film, “The Interview,” which is a comedy that features a plot to assassinate the North Korean leader.

“The world will be full of fear,” the group wrote in a message. "Remember the 11th of September 2001. We recommend you to keep yourself distant from the places at that time.”

"Whatever comes in the coming days is called by the greed of Sony Pictures Entertainment," read the message.

The hackers warned that they “will clearly show it to you at the very time and places ‘The Interview’ be shown, including the premiere, how bitter fate those who seek fun in terror should be doomed to.”

The threat prompts Sony to allow theater chains to cancel showings of the movie.

Actors Seth Rogen and James Franco are television journalists in the movie and they were involved in a CIA plot to kill Kim Jong-un. It is set to open across the United States on Christmas Day.

In summer, North Korea warned that the film’s release would be an "act of war that we will never tolerate."  The government of North Korea denied any involvement in the hack.

The hackers group has also released a trove of data files calling it “Christmas gift”. It includes 32,000 emails to and from Sony Entertainment. It already released a cache of Sony’s emails, social security numbers and salary details.

The Federal Bureau of Investigation and the Department of Homeland Security announced that they were investigating the threats.