North Korea’s already shaky Internet has gone fully dark, several media outlets are reporting today, citing experts and sources inside the country. The shutdown, if that’s what it is, comes just days after President Barack Obama said the U.S. “will respond proportionally” to North Korea’s cyber attack on Sony Pictures. The Associated Press reported today that the White House and the State Department declined to say whether the U.S. government was responsible for the alleged shutdown.

Obama’s statements Friday came after the FBI said the North Korean government instigated the massive cyberattack.

Sony HackedAs for today’s alleged outage, the New York Times quoted Doug Madory, director of Internet analysis at Dyn Research, as saying the North Korea telecom lines — mostly routed through Chinese-operated networks — began experiencing issues over the weekend. Madory said the outage was consistent with a DDoS attack, the denial-of-service technique hackers use to overwhelm networks with traffic until it breaks down.

North Korea has denied involvement in the Sony hack that exposed massive amounts of personal and company data beginning November 24. The hackers known as Guardians of Peace claimed the action was in response to the studio’s making of The Interview, a satire about an imagined assassination of North Korean leader Kim Jong-unSony eventually scrapped the comedy’s December 25 release. In an interview Friday on CNN, Sony CEO Michael Lynton said the studio “would still like the public to see” the movie. Sony says no major alternative distributors have yet agreed to release it.

Over the weekend, North Korea suggested a joint probe to find the culprit. But it has also threatened action against the U.S. should it follow through with Obama’s statements Friday.