South Korea revealed that North Korea has amassed a “cyber army” made up of 6,000 members, and the unit is aiming to disrupt South Korea's military and government, the AP reported on Tuesday, adding North Korea was previously thought to have a cyber army of about 3,000 members.

In a report, the South Korean Defense Ministry said that the North Korean cyber army is dedicated to “paralyzing the South psychologically and materially,” and that it has already carried out attacks against South Korea's military operations and main government systems, according to the AP story.

The AP also reported that North Korea has made advancements in missile technology and may have the ability to strike the U.S. mainland. Furthermore, North Korea has made progress in developing miniaturized nuclear warheads to mount on the missiles, the AP report adds.