(CNN) — Internet service in North Korea was intermittent on Tuesday, according to Dyn Research, a company that monitors Internet performance.
“North Korea continues its struggle to stay online,” the company announced on Twitter on Tuesday morning.
The situation was worse earlier, when the entire nation lost service for about nine hours.
Internet service appeared to have been restored before becoming spotty again, Dyn Research said.
The disruption came amid an escalating war of words between the United States and North Korea over a massive cyberattack on Sony Pictures.
“Usually there are isolated blips, not continuous connectivity problems. I wouldn’t be surprised if they are absorbing some sort of attack presently,” Doug Madory, director of Internet analysis at Dyn Research, said when the Internet was down.
Matthew Prince, president of CloudFlare, a performance and security company, said the disruption looked as if “all the routes to get to North Korea just disappeared.”
“It’s as if North Korea got erased from the global map of the Internet,” he said.
Prince, who also spoke when North Korea’s Internet was down, told CNN it’s well within the realm of possibility that a single individual could have been behind the interruption but said he can’t conclude at this point that an attack took place.
“If it is an attack, it’s highly unlikely it’s the United States. More likely it’s a 15-year-old in a Guy Fawkes mask,” he said.
The outage brought down sites run by the Korean Central News Agency and the Rodong Sinmun — major mouthpieces for the regime — according to the South Korean news agency Yonhap.
There were no problems accessing pro-Pyongyang pages that have servers abroad, Yonhap reported.
The United States blames North Korea for the Sony hack; North Korea denies it was involved.
The regime is upset over Sony’s controversial comedy, “The Interview,” which follows a plot to assassinate its leader, Kim Jong Un.
The studio decided to pull the film amid threats to moviegoers.
U.S. President Barack Obama told CNN on Sunday that the hack was “an act of cybervandalism that was very costly, very expensive” but that he didn’t consider it an act of war.
He had previously said that the United States would “respond proportionally” to the attack on Sony, without giving specifics.
A spokeswoman for the National Security Council declined to comment on the reported outage.
A State Department spokeswoman similarly deflected a question about the disruption.
“We aren’t going to discuss — you know — publicly, operational details about the possible response options or comment on those kind of reports in any way, except to say that as we implement our responses, some will be seen, some may not be seen,” Marie Harf told reporters.
CNN’s Samuel Burke, Jose Pagliery and Jethro Mullen contributed to this report.
By Ralph Ellis and Dana Ford