Two brothers from Old Trafford, Manchester, have most likely been killed fighting alongside the Islamic State (Isis) in Syria, sources close to their family have said.

Khalif Sharrif, 21, and his younger brother Abdulrahman, 18, travelled to Syria in November 2014 to fight for the Isis (Daesh). Individuals close to the family and community told the Manchester Evening News that Abdulrahman was believed to have been killed in combat and Khalif was missing, presumed dead.

Mohammed Shafiq, chairman of the Greater Manchester-based Ramadhan Foundation, said the Islamic State had communicated with the Sharrif family, which has ties to both Kenya and Somalia, to pass on the information. A neighbour said they were devastated by the news.

The family alerted police when the brothers fled Britain. They arrived in the UK from Kenya before the young men were born, over 20 years ago.

The Sun reported that the brothers were childhood friends with Manchester United footballer Sadiq El Fitouri, who lives on the same street as their parents. "It's a mad situation. They were great lads, just normal guys who used to play football with us and go to the gym," he was quoted as saying.

"Our families have known each other for years. I just can't believe they've done this. There was never any sign," he added.

According to Facebook pages, apparently set up by the pair, Khalif Sharrif is understood to have attended Stretford Grammar and South Trafford College. Abdulrahman attended the University of Central Lancashire and attended Loreto Sixth Form College and Stretford High School.

According to an anonymous friend interviewed by the Manchester Evening News, Khalif used to work at Apple and attended university for five or six months before he went to Syria. "They never showed any signs of being extremists. To look at them, or talk to them, you'd never have known," he was quoted as saying.