A terrorists group has claimed responsibility for today's attacks in Oslo, Norway--which included the bombing of the Prime Minister's office and a massacre at a children's day camp by a gunman dressed as a police officer--using social media.
An obscure group called Ansar al-Jihad al-Alami (Assistants of the Global Jihad) posted a message on an Islamist bulletin board called Smukh and may have uploaded a video to YouTube several days ago predicting the attack, in which at least seven people were killed.
Ansar al-Jihad's Abu Sulayman al-Nasir allegedly posted a message claiming responsibility for the Oslo attacks  on the Arabic-language jihadist forum Shamikh. According to a partial translation by terrorism expert Will McCants of Jihadica , al-Nasir claims the attacks were in retribution for the occupation of Afghanistan by foreign troops and unnamed insults to the Muslim prophet Muhammad. Al-Nasir also threatens further attacks:
We have warned since the Stockholm raid of more operations and we have demanded that the countries of Europe withdraw from the land of Afghanistan and end their war on Islam and Muslims. What you see is only the beginning and there is more to come.
The “Stockholm raid” reference is in response to a 2010 suicide bombing in Sweden .
The original post on Shamikh was taken offline  and apparently replaced by the terrorist version of a 404 page.
Commenters on Twitter are also claiming that a Polish-language video uploaded to YouTube several days ago and taken later taken offline predicted terrorist attacks in Oslo . However, since the video is not available, the veracity of this claim is unknown. An alleged cache of the YouTube clip  is shown below.
The Norwegian Prime Minister's office was hit by what appears to be a sophisticated car bomb, and a gunman opened fire on a day camp in Oslo affiliated with the Norwegian Labor Party. An exact casualty count is not known, but Norwegian Prime Minister Jens Stoltenberg is unharmed.
This is an ongoing story; media sources are still unclear on the number of bombs that have gone off in Oslo, the number of casualties, and what exactly happened at the day camp shooting. We recommend checking the Twitter feeds of the New York Times , BBC , and Norwegian journalist Rune Håkonsen  for the latest.
Update: As of Saturday afternoon New York time, this story has become even more complicated. The gunman arrested at the site of the massacre, a Christian fundamentalist right-winger named Anders Behring Breivik, appears to have no connection with any jihadi group. However, Breivik did leave a lengthy trail of social media breadcrumbs. At least 90 are confirmed dead in the attack and authorities report the number is likely to be much higher.
Shortly after the Shamikh post was taken down claiming responsibility for the blast, another post was written by Abu Sulayman al-Nasir claiming that his statement "was not an official statement" and that the real attackers would be "known by all."
The real question now is what Breivik's methods, motives and greivances were. The "Assistants of the Global Jihad" posted their message claiming responsibility for the blast to a closed, restricted forum  nonetheless monitored by counterterrorism experts; the university professor who first reported it, Will McCants, has had a track record of reporting accurate information about extremist groups.
Ultimately, this unknown "Assistants of the Global Jihad" organization claiming responsibility for the attack took much of the media by surprise. That's the problem with false confessions; others are likely to take them seriously.
Updated: Saturday May 23, 14:06 EST
[Top Image: Flickr user Johsgrd ]