The Islamic State (IS) has threatened to kill Twitter co-founder Jack Dorsey and his employees after the micro-blogging site banned several of the extremist group's accounts.

According to the International Business Times , IS, in an Arabic message titled ‘Twitter in range of Caliphate’, urged jihadists around the world to retaliate against Twitter for kicking the group off the micro-blogging site.

The report said IS’ message was posted on JustPaste.it , a platform usually used by the group’s militants.

It read: “Your virtual war on us will cause a real war on you. You started this failed war... We told you from the beginning it’s not your war, but you didn’t get it and kept closing our accounts on Twitter, but we always come back.”

“But when our lions come and take your breath, you will never come back to life,” added the message, which also carried an image of Dorsey with a target over his face.

The group had in September last year issued similar threats after its Twitter accounts were closed down, said the report.

Twitter, in an immediate response, said it is checking the authenticity of the threat.

“Our security team is investigating the veracity of these threats with relevant law enforcement officials,” it was quoted as saying by Buzzfeed.

IS has captured large swathes of area in Iraq and Syria as governments failed to halt its advance.

Supporters from across the world have joined the fight in the region, raising international concerns the group may launch attacks beyond the Middle East.