IS

The hijacking of the Justin Bieber hashtag occurred in the early hours of Friday, with links to the video, titled "Message to Islamic West", also carrying the hashtags of ISIS and ISIL, by which Islamic State is also known, as well as the Bieber hashtag.

The 21-year-old has almost 74 million Twitter followers.

The video purports to show militants carrying IS flags and the heavily armed commanders of the groups that had declared their allegiance to IS leader Abu Bakr al-Baghdadi.

The groups have, in the past, separately claimed support for IS, but the video suggests they might have agreed to consolidate their forces, creating an even more potent threat from the lawless island region bordering Malaysia.