By Duncan Gardham, Investigations Correspondent

The two men, one a former accountancy student, had travelled to a religious school to study Islam but took up arms in Yemen’s increasingly bloody civil war, their friends and relatives told the Daily Telegraph.

They were killed fighting rival shia Muslims in the mountains around the small town of Dammaj in Northern Yemen, according to one report.

It comes as Jonathan Evans, the director general of MI5, warned that Yemen has become a destination for a small number of British “would-be jihadis” seeking to use the Arab Spring for training and militant activity.

The father of one of the men said he considered his son to be “shaheed” [a martyr] and his whole family had been inspired to adopt fundamentalist Islam.

Both men attended a small mosque in Cranford, West London, under the flight path into Heathrow, which was also occasionally attended by Asif Hanif, Britain’s first suicide bomber. Hanif killed himself in an attack on a waterfront bar called Mike’s Place in Tel Aviv in 2003.

An imam at the mosque said they did not agree with suicide bombing or terrorism but they would not discourage members of the congregation from traveling to Dammaj, which is considered a seat of learning for fundamentalist “salafi” Islam.

Adil Malik, 24, from Hounslow, and his friend, Hisham, had been living in Dammaj for several years, studying with Sheikh Yahya al- Hajooree, who runs a madrassa called Dar ul-Haadith.

The seminary is said to have several thousand students from all over the world, including dozens from Britain but has come under regular attack from shia Houthi tribesmen.

The sheikh made a call to arms in a video posted online two months before Mailk died, declaring: “Whoever is killed defending his faith has died a martyr.”

More here.