A weekend attack on North Korean websites staged by members of the Anonymous hacker group appears to have caused some problems for the sites.

Connections to several major Pyongyang-based sites, including the Korean Central News Agency and Voice of Korea, were slow although successful in several tests done in the first few hours of the coordinated attack, which began at 1am GMT on Sunday.

Those results are in contrast to a previous series of attacks that took the sites offline for days. That difference was acknowledged by an Anonymous Korea Twitter message:

North Korea has reconfigured its Internet connection since the last round of major attacks. Previously its Internet servers were connected to the rest of the Internet via only two links: a link to China Unicom and a back-up satellite connection. Now a third link, to China Unicom Hong Kong, has been added.

It’s not clear if the difference in effectiveness this time around was due to the smaller scale of the attack or the new connection.

Since before this weekend’s attacks, Anonymous hackers have been promising a large campaign against North Korean sites on June 25, which is the anniversary of the start of the Korean War.