Islamic State threatens to kill British hostage David Haines next, Cameron summons an emergency meet

London: Islamic State militants have threatened to execute a captive Britain aid worker David Cawthorne Haines after the brutal killing of US journalist Steven Sotloff in the latest video released by the terror outfit.

Shortly after the video was released, UK Prime Minister David Cameron said that if the authenticity of the video is verified, then it is a “despicable and barbaric murder.” He added that his prayers and thought's are with Sotloff's family.

Meanwhile, Cameron will be chairing a Cabinet Office Briefing Rooms (COBR) meeting on Wednesday to review the latest development.

“We have already been working hard to keep British people safe and we will continue to do all we can to protect our country and our people from these barbaric terrorists,” a statement issued by Cameron stated.

“ISIL terrorists speak for no religion. They threaten Syrians, Iraqis, Americans and British people alike and make no distinction between Muslims, Christians or any other faith,” Cameron further said.

PM: If verified, this is a despicable and barbaric murder. My thoughts are with Steven Sotloff's family. http://t.co/kgIc6bFUka — UK Prime Minister (@Number10gov) September 2, 2014

Haines is a former British soldier who was abducted in 2013 in Syria. He has earlier worked with Non-violent Peaceforce in South Sudan for six months and was working with some other organisation at the time of his abduction.

The gruesome video titled "A Second Message to America," reportedly shows an IS militant warning Britain and other governments to not enter into “this evil alliance of America against the Islamic State.”

31-year-old Sotloff is the second journalist to be murdered in Syria by Islamic militants in the last two weeks.

It has several similarities with the video of the beheading of US journalist James Foley.

The chilling video shows Sotloff sitting on his knees wearing an orange jumpsuit with his hands tied behind his back, just like Foley, while a British-accented IS militant is seen standing next to him covered in black clothes with a knife in his hand.

In a pre-written statement, Sotloff is seen saying, “Obama, your foreign policy of intervention in Iraq was supposed to be for the preservation of American lives and interests. So, why is it, that I am having to pay the price for your interference with my life?”

The video then shows the executioner condemning the air strikes in Iraq before beheading Sotloff and threatening US President Barack Obama, “Your air strikes continue to strike our people, our knife will continue to strike the necks of your people.”

Shortly after the video was released, the US State Department spokesperson, Jen Psaki, said that if the video is genuine then, “we are sickened by this brutal act.” She further paid condolences to Sotloff's family.

Watch: Statement from @statedeptspox Psaki on the murder of Steven Sotloff. http://t.co/RQgllSLc01 — Department of State (@StateDept) September 2, 2014