A new round of attacks against North Korean websites began Saturday, causing several to become unavailable.

The attacks appear to be part of a loosely coordinated effort by hackers to target North Korean sites after the country’s state-run media said relations with South Korea were “at a state of war.”

As of 3pm Korean time (0600 UTC) on Saturday, attempts to contact the Naenara, Korean Central News Agency, Air Koryo and Voice of Korea all failed.

The sites were hit with an apparent DDoS (distributed denial of service) attack in which the web servers are flooded with so much junk traffic from hackers that they become overloaded and cannot handle requests from normal users.

On Twitter, messages were being grouped with the #OpNorthKorea hash tag.

Some apparently calling for attacks on certain sites.

And others marking the successful takedown of a website.

At time of writing the third site on that list, korea-dpr.com, is still available. The site is the home page of Alejandro Cao de benos’ Korean Friendship Association and appears to be hosted in The Netherlands.

It’s impossible to know who is really behind the attacks, but judging by Twitter messages the cyber call to arms appears to have attracted a small group of people.

The attacks began several hours after state-run Korean Central News Agency (KCNA) said “From this moment, the north-south relations will be put at the state of war and all the issues arousing between the north and the south will be dealt with according to the wartime regulations.

The statement is the latest in an increasingly hard line of rhetoric from the DPRK. The last few days have seen North Korea directly threaten to attack the United States and its military bases while the U.S. has flexed its muscle by overflying South Korea with a B-52 and B-2 bomber.

Despite the heightening tensions, many observers don’t expect the DPRK to follow through with its threats and many again believe any such attack would attract a swift and hard response by South Korean and/or U.S. forces.