Thousands of young British Muslim men have rallied against radical Islam amid concerns that British jihadists are fighting in Syria.
An estimated 5,000 Muslims gathered in Surrey today to pledge loyalty to Britain in light of concerns over the popularity of the extremist militant group Islamic State in Iraq and Syria (Isis), and the alleged involvement of Britons.
The three-day residential event, organised by the Ahmadiyya Muslim Youth Association (Amya), has brought together 5,000 young British Muslim men from England, Scotland and Wales, to foster bonds of brotherhood and affirm their pride in being British and Muslim.
The Caliph, His Holiness Hazrat Mirza Masroor Ahmad, spiritual leader to tens of millions of Muslims across the world, said: "Britain has provided a home for people from across the world. As Ahmadi Muslims, we give thanks to Queen and country for allowing us to practise our faith freely.
"Islam teaches us to be loyal to the country in which we reside and, as Ahmadi Muslims, we believe it is our duty to serve the country, to contribute to society and promote peace and good citizenship.
"When we say Islam means peace, we practise that very fact and demonstrate it with our actions. Our ethos is love for all, hatred for none."
Amya spokesman Adam Walker said: "Isis represents an abhorrent manipulation of Islam and we are here to say loud and clear 'No to extremism'."
It came as the Security Service today made tracking British jihadists fighting in Syria its top priority, after a video emerged apparently showing Britons in the country urging UK Muslims to join insurgents there and in Iraq.
In the 13-minute video, entitled There Is No Life Without Jihad, three British fighters announce that they are preparing to travel to Iraq to fight there.
One of the men in the film is a 20-year-old aspiring medical student from Cardiff.
Nasser Muthana, who goes by the name Abu Muthanna al-Yemeni, travelled to Syria with his 17-year-old brother, Aseel Muthana, after disappearing in November.
His father, Ahmed Muthana, told the Daily Telegraph that his elder son had been accepted at four universities to study medicine but did not go.
Instead he thinks Muthana, who went to Cathays High School, gained 11 GCSEs and enjoyed swimming and football, became "brainwashed" and radicalised in the UK.
Muthana is one of three apparently British men who appear in the video, which calls for their countrymen to "answer the call and fight for Allah".
Mr Muthana t old the Telegraph that the family had been informed a few weeks ago that his son was in Turkey, and said the views expressed in the video were not his son's real opinions.
And he told told ITV News that watching the footage of his son had made him cry.
"I wish I could hold him, hold his hand, ask him to come back," he said.
The Government is treating the growing threat from Isis with ever-greater seriousness.
On Thursday the terror group was added to a list of banned organisations, making it an offence to be a member. Four other Syria-linked terror groups were banned at the same time.
Prime Minister David Cameron has insisted "everything that can be done is being done" to stop Britons being radicalised overseas amid fears that 450 people have joined the ranks of the extremist group in Iraq.
The BBC reported that MI5 has made tracking British jihadists fighting in Syria its top priority.
Experts believe the method of appeal in the video mimics that of Western charities and aid groups.
The Home Office said: "We do not tolerate the existence of online terrorist and extremist propaganda, which directly influences people who are vulnerable to radicalisation.
"We already work closely with the internet industry to remove terrorist material hosted in the UK or overseas."
Sir Peter Fahy, who leads on the Prevent counter-terrorism strategy for the Association of Chief Police Officers, said around 500 Britons had travelled to Syria and Iraq - a higher estimate than the 400 claimed by Foreign Secretary William Hague.
He said "huge amounts of material" was being taken down from the internet every week as part of the effort to stop people being radicalised.
The Greater Manchester Police Chief Constable warned against "demonising the Muslim community itself" and said: "The vast majority of Muslim people are really worried about this situation and are working with us to try and identify those people that may be at risk."
Concerns about Islamist extremism in British society have been heightened by the so-called Trojan Horse plot in Birmingham schools, but Sir Peter stressed the importance of working with Muslim communities.