Seoul, Dec 23 (IANS): North Korea's Internet connectivity was restored Tuesday after an over nine-hour outage, said Dyn Research, a company which monitors Internet performance.

The disruption had occurred amid an escalating war of words between the US and North Korea over a massive cyber attack on Sony Pictures following a controversy over the Seth Rogen film about a plot to assassinate North Korean leader Kim Jong-un.

"North Korea's Internet restored after 9 hours and 31 minute outage," CNN quoted Dyn Research as tweeting.

Matthew Prince, the president of CloudFlare, a performance and security company, described the disruption 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.

Earlier, Prince had said it's well within the realm of possibility that a single individual could have been behind the interruption but he said he couldn't conclude at that point that an attack took place. "If it is an attack, it's highly unlikely it's the US. More likely it's a 15-year-old in a Guy Fawkes mask."

The outage brought down sites run by the Korean Central News Agency and the Rodong Sinmun -- prominent mouthpieces for the regime -- according to the South Korean news agency Yonhap.

The US had blamed North Korea for the cyber attack on Sony, which had led to the theft of extensive amount of proprietory Sony employee data.

The North Korean government, which was outraged by a film's storyline, claimed to have "clear evidence" that the US government engineered the project as a "propaganda" attack against the country, media reports said.

However, it has denied being involved in the attack and proposed a joint investigation with the US.

Sony had decided to cancel the Christmas release of the film, in the wake of the cyber attack, amid threats to movie-goers.

US President Barack Obama told CNN Sunday that the hack was "an act of cybervandalism", but he did not consider it as an act of war.