British Muslims condemn Alan Henning's beheading

Prayers for Alan Henning were said in mosques throughout Britain at the start of the Eid al-Adha festival.

FILE: Prime Minister David Cameron makes a statement to the media at Number 10 Downing street in London on 14 September, 2014 on the killing of British aid worker David Haines by IS millitants. Picture: AFP.

LONDON - Muslim groups across Britain united on Saturday to join Prime Minister David Cameron in condemning the beheading of aid worker Alan Henning by Islamic State insurgents.

Prayers for the 47-year-old taxi driver were said in mosques throughout Britain at the start of the Muslim Eid al-Adha festival, as his family said they were numb with grief.

Cameron called Henning a gentle, compassionate man who had simply tried to help others, and said Britain would do all it could to destroy his killers.

British media had focused on Henning as an ordinary, middle-aged non-Muslim who had given up his time and left behind a wife and two teenage children to help Muslim friends drive informal aid convoys to the victims of Syria's civil war.

"We will use all the assets we have ... to defeat this organisation, which is utterly ruthless, senseless and barbaric in the way it treats people," Cameron said in a televised statement after meeting the heads of Britain's armed forces and intelligence agencies.

Henning had been held in Syria for nine months before a video was posted on YouTube on Friday showing him kneeling against a desert setting before a masked man holding a knife.

The man spoke briefly with the same southern British accent as the killer of previous hostages, widely dubbed "Jihad John".

A second video featuring an unmasked, apparently British fighter pouring scorn on Cameron for failing to send in ground troops was being urgently examined by police on Saturday, Cameron's office said.

Henning was the fourth Western hostage to be beheaded by Islamic State, which has been attacked by US, British, French and Arab fighter jets since seizing swathes of Iraq and Syria.

His case had prompted a wave of appeals for his release from British Muslim leaders.

Shuja Shafi, Secretary General of the Muslim Council of Britain, called his murder "a despicable and offensive act".