A Facebook message claiming to show video footage of the car bomb that tore through a Norwegian government building in Oslo is a scam, security experts warn.

The scam has spread across thousands of Facebook profiles and is infecting one user every second, reports technology website Help Net Security. So far, no video of the blast has been released.

The message appears on a user's wall and reads: [Video] OSLO Security Camera Captures Blast!

Users who click on the link will be redirected to a fake YouTube video player, the security firm Sophos warns.

Victims of the scam are then prompted to prove they are at least 18 years of age before completing an IQ test and entering their mobile phone number to view the video.

They will be sent text messages four times a week with trivia questions, with each question costing them $2.

If a user has already been hit by the scam, Sophos recommends removing the entry from their newsfeed and to make sure the link has not crept under their profile's "Likes" section. Mobile Marketer also recommends victims contact their mobile provider and to contact their bank.

This is not the first time Facebook users have been cautioned to be wary of fake viral video links.

Just hours after news broke that Osama bin Laden had been killed, a video scam spread virally on the social media site.

Similar to the Oslo scam, curious users were prompted to click on a link, masking as a wall update, which allowed them to view banned video footage of bin Laden's death.

Earlier this month, Facebook reported that the supposed leaked video of Casey Anthony confessing to her lawyer was also a scam.

The post, like the Oslo scam, appealed to news junkies.

It read: "BREAKING NEWS - Leaked Video of Casey Anthony CONFESSING to Lawyer!"