ISIS claims beheading of US hostage Peter Kassig

The Islamic State terror group has claimed to have beheaded American hostage Peter Kassig, an aid worker and former Army Ranger, in a graphic new video.
In the nearly 16-minute video uploaded to social networks on Sunday, a black-clad militant with his face concealed stands before a severed head that he claims is that of the U.S. aid worker.
"If confirmed, we are appalled by the brutal murder of an innocent American aid worker and we express our deepest condolences to his family and friends," Meehan said. The video was posted shortly after President Obama departed for Washington from the G-20 summit in Australia.
Ed and Paula Kassig, Peter's parents, released a statement early Sunday saying they were aware of the reports of their son's death and were awaiting confirmation of their authenticity. They also asked that media outlets not post any images or video distributed by Islamic State, better known as ISIS.
"We prefer our son is written about and remembered for his important work and the love he shared with friends and family," the statement read, "not in the manner the hostage takers would use to manipulate Americans and further their cause."

TIMELINE OF BRUTAL ISLAMIC STATE KILLINGS  

The murder of US aid worker Peter Kassig was the fifth such killing to be filmed and released by the Islamic State (IS). Here is a timeline of events, starting with the days leading up to the death of the first hostage, US journalist James Foley.

• Summer 2014 - A rescue mission fails to free Mr Foley from a secret location where he is being held by IS. The American freelance journalist, 40, was captured two years earlier.
• August 13: Mr Foley's family receive a message that he will be murdered.
• August 19: al-Furqan Media, which is controlled by the terror group, releases a video appearing to show Mr Foley's killing. His death apparently happened at some time in the previous week. Social media bosses are forced to act swiftly in banning both the video and still images of the beheading, while concerns mount for fellow reporter and captive Steven Sotloff, who is seen pleading for the US to stop air strikes in Iraq at the end of the video.
• August 20: David Cameron cuts short a family holiday in Cornwall to hold meetings in Downing Street over the 'shocking and depraved' murder. Meanwhile, US President Barack Obama remains defiant over his country's war on terror. He says: 'We will be vigilant and we will be relentless.'
• August 21: The killer is reported to be a British man who goes under the moniker 'Jihadi John'.
• September 2: Mr Cameron condemns the 'disgusting and despicable' video apparently showing Mr Sotloff wearing an orange jumpsuit and being beheaded by IS militants. The alleged killer speaks with a British accent, prompting suggestions he is the man who murdered Mr Foley. It emerges that a British hostage, now known to be aid worker David Haines, is also under threat.
• September 4: At the start of a Nato summit in Wales, leaders of the Western alliance show a united front in response to terror threats. Mr Cameron and Mr Obama insist they will not weaken in the face of threats from IS terrorists. The Prime Minister refuses to rule out joining the US in air strikes on IS. He says Britain must 'use everything we have in our armoury' to squash the terrorists out of existence.
• September 5: Foreign Secretary Philip Hammond joins Mr Cameron in saying the Government will not hold back on launching air strikes, and says threats on Mr Haines's life by his captors will not deter the UK from taking action. The Nato summit ends with a pledge to 'degrade and defeat' IS militants.
• September 9: Defence Secretary Michael Fallon confirms Britain will supply £1.6 million of machine guns and ammunition to Kurdish forces fighting IS militants in northern Iraq as part of a burgeoning international effort to drive back the jihadists.
• September 10: Mr Obama authorises air strikes inside Syria for the first time as well as an expansion of strikes in Iraq.
• September 13: A video showing the murder of British aid worker Mr Haines is released. The video, which involves the 44-year-old saying Mr Cameron and former PM Tony Blair should be held responsible for his death, is widely condemned. It comes hours after Mr Haines's family issue a plea to his captors to contact them. The clip also includes a threat to kill a second British hostage.
• September 14: Mr Cameron calls an emergency meeting of its Cobra committee in the wake of the murder. The next British hostage, 47-year-old minicab driver Alan Henning, is named as the man shown in the video.
• September 19: Islamic militants release a propaganda video featuring a British hostage believed to be journalist John Cantlie.
• September 23: Islamic extremists release a new propaganda video appearing to feature Mr Cantlie. The clip is the second showing the journalist to be circulated by IS militants in less than a week. It comes as the US - backed by Arab allies - carries out its first wave of air strikes on IS militants in Syria.
• September 24: Britain appears ready to ramp up its military involvement in the struggle against IS, as Mr Cameron addresses the United Nations in New York.
• September 25: FBI director James Comey is reported to have confirmed that the identity of Jihadi John has been uncovered. However, he refused to give the individual's name publicly.
• September 26: MPs vote by 524 to 43 to endorse attacks on the militants in Iraq in support of the United States-led coalition. The vote clears the way for RAF warplanes stationed in Cyprus to begin combat operations as soon as suitable targets are identified.
• September 27: RAF Tornado GR4 fighter bombers carry out their first sortie over Iraq since Parliament gave the green light for air strikes without finding any targets to attack.
• October 3: A video showing the brutal murder of Mr Henning, 47, by IS militants is posted on the internet. Mr Cameron vows to 'hunt down' the 'repulsive' terrorists responsible for the beheading.
• October 7: Former Guantanamo Bay detainee Moazzam Begg claims he offered to help the Government secure the release of Mr Henning but was rebuffed. Mr Begg says he believed he knew those who held the murdered aid worker and had helped secure the release of hostages from extremists in Syria in the past.
• October 13: Mr Cantlie's sister urges IS to 'restart dialogue' with his family.
• November 16: IS releases a video showing the beheading of American hostage Peter Kassig. The IS militant in the footage speaks with a London accent and appears to be Jihadi John. Mr Kassig was captured in Syria in October 2013 while providing medical training and humanitarian aid to victims of the country's conflict.