Has North Korea doubled the size of its cyber army?

The government of North Korea has decided to double the size of its "cyber army", said the South Korean Defence Ministry on Tuesday.

The number of troops now amounts to 6,000 members and the ministry claims their goal is to cause "physical and psychological paralysis" in the South.

These figures have been published in a whitepaper after the recent hack attack on Sony Pictures that was apparently done by North Korean hackers infuriated by the movie "The Interview".

"North Korea is currently running its 6,000-member workforce for cyber warfare and performing cyber-attacks for physical and psychological paralysis inside South Korea, such as causing troubles for military operations and national infrastructures," the paper said.

North Korea claimed it had nothing to do with the recent attacks on Sony that resulted in the leaking of many classified documents, as well as a couple of unreleased movies.

“It is common sense that the method of cyber warfare is almost similar worldwide. Different sorts of hacking programs and codes are used in cyber space," the government said.

"Our toughest counteraction will be boldly taken against the White House, the Pentagon and the whole US mainland."

The FBI recently claimed otherwise: "As a result of our investigation ... the FBI now has enough information to conclude that the North Korean government is responsible for these actions".

North and South Korea have remained technically at war for more than six decades as the Korean War ended in an armistice, not a peace treaty.