By Angus Berwick
CARDIFF (Reuters) - For the Muslim community in Reyaad Khan's neighborhood of Cardiff in Wales, this week's news he had been killed by Britain in a drone strike in Syria was just the latest in a series of shocks about radicals in their midst.
Three years ago, two brothers from the same area, Riverside, were jailed for plotting to bomb the London Stock Exchange as part of a campaign of al Qaeda-inspired attacks across the British capital in the run-up to Christmas.
An ethnically mixed district described by one resident as a "mini United Nations", Riverside differs from much of the Welsh capital only in that some front doors are inscribed with Arabic inscriptions and Halal butchers abound.
Khan, 21, who community members said had been polite and ambitious as a schoolboy, secretly packed his bags in 2013 and slipped out of the two-storey terraced family home where he had lived all of his life.
He and two others from neighboring Butetown, Aseel Muthana and his older brother Nasser, joined Islamic State and became poster boys for its recruitment drive in the west.
Mohammed, 17, who used to play football with Khan and was friends with Aseel Muthana, said the young runaways had unnerved the Muslim community well before the government said he had been planning to attack Britain.
"People are more cautious about who they talk to," he said.
He and others who knew Khan at the Al-Manar Centre in central Cardiff, where he prayed and studied Islam, said they believed he had been radicalized through extremist websites and social media in his bedroom, rather than by a local preacher.
"It's most likely they got him through the internet," said Mohammed. "They taught him another kind of Islam."
Mohammed Islam, a former local counselor and friend of the Khan family, who were originally from Bangladesh, blamed "evil internet clerics," but said the family was still not clear exactly how he was influenced.
Khan and two other Islamic State associates, including Briton Ruhul Amin, were driving in a vehicle in Raqqa, the de facto capital of Islamic State, when they were killed in the strike on August 21.
Prime Minister David Cameron described it as an act of self defense, saying they were "seeking to orchestrate specific and barbaric attacks against the west, including directing a number of planned terrorist attacks right here in Britain, such as plots to attack high profile public commemorations".
Speaking to parliament on Monday, he said striking a British citizen abroad outside a traditional theater of war was a new departure. Opposition lawmakers have demanded a review of the decision making.
Khan began to show a more radical side in 2013 when he won a place at the ultra-conservative Madinah University in Saudi Arabia, but ended up not accepting it, local media said.
When he left Britain, following the path taken by at least several hundred young British Muslims and thousands of young men and women across Europe, his destination was Syria.
Cast as 'Brother Abu Dujana al Hindi', Khan surfaced among the so-called Islamic State fighters who have taken control of swathes of Syria and Iraq while justifying the rape of non-Muslim women and glorifying the beheading of enemies.
In one tweet from 2014, Khan said he had seen "the longest decapitation ever. And we made sure the knife was sharp. Brother who was next decided to use the glock (pistol) lol (laugh out loud)."
For those who knew him in Cardiff, Khan's glorification of such violence contrasted with the studious, football-loving boy who achieved 12 GCSEs - the exams British teenagers take at around 16 - including two with top marks of A*.
"He was a jolly boy, well-mannered and very cooperative in the community," said Islam. "He was ambitious ...Nobody expected him to go on to do the things he did."
Islam said Khan, who was pictured in 2009 next to former Labour minister Ed Balls at a youth club, played a prominent role in local youth politics.
In a film obtained by the Guardian Newspaper recorded at a Cardiff youth center where Khan was involved, he spoke about the problems of growing up in a deprived inner-city area and of being stereotyped due to his age and ethnicity.
"The world can be a lovely place but you've just got to get rid of the evil," said Khan.
He made clear his political aspirations in a Facebook post in October 2010. "I need 2 become the 1st Asian Prime Minister!" he wrote.
By 2014 he had very different ambitions. In a video entitled "There's No Life Without Jihad", wearing a khaki uniform with his face shaded by a checkered head scarf, Khan beckoned "the brothers who have stayed behind" to join him.
"You need to ask yourselves ... what prevents you from attaining martyrdom and the pleasure of your lord," he said.
On the quiet street where he grew up, the blinds at his home were closed as his family mourned. His mother, Rukia, declined to comment.
Mohammed Islam said he and the Khan family wanted to see the legal advice the government received to justify the attack. He said the family would be in touch with their lawyers.
Kevin Brennan, the lawmaker for Cardiff West, said Khan's death was no surprise but its nature left a lot to be explained.
"It was perhaps inevitable that Reyaad Khan would die in violent circumstances given the choice he made to leave his home and parents in Cardiff and travel to Syria to join ISIL," he said, using an alternative name for Islamic State.
"There are however many questions that the government needs to answer about the nature of the threat they say that he posed to Britain which they have used to justify this unprecedented action."
(Editing by Guy Faulconbridge and Philippa Fletcher)