The Taliban are thought to be recruiting an increasing number of fighters from Britain after RAF experts overheard secret transmissions from the Afghan frontline spoken in broad Midlands and Yorkshire accents.
Specialists in top secret surveillance planes listened in on radio traffic broadcast by the Taliban in Helmand province and heard fighters talking in thick regional accents.
The discovery indicates that a growing number of British-born Muslims are turning their backs on the West and moving to Afghanistan to be trained as fighters.
It has been reported that RAF radio operators were able to hear the young fighters speaking in clear Bradford and West Bromwich accents.
The linguistics experts were listening to the conversations from specially adapted Nimrod planes flying above the province.
The Taliban reportedly spoke mainly in Afghan Persian or Pashto – but when they were stuck for words, they would slip back into their native language.
“The mission specialists could easily jam the Taliban transmissions but the RAF believes listening in to their plans is much more productive,” a source said to The Sun.
“It was quite startling to hear English being spoken with clear Bradford and West Brom accents.
“They reverted to English when they couldn’t remember the Afghan Persian or Pashto – the two local languages – for certain words.”
The newspaper said that the transmissions were picked up by three converted Nimrods that are usually based at RAF Waddington, Lincolnshire, with 51 Squadron.
The planes fly at more than 40,000ft and with language specialists on board who operate surveillance equipment known as “The Package”.
General Sir Anthony Walker, former deputy chief of the defence staff, said: “We seem to have confirmation that fanatical jihadists from Britain are working on the frontline of the the war in Afghanistan.
“Eavesdropping seldom has a good image.
“But let’s hope the perseverance and dedication of our listeners-in-the-sky continues to save the lives of our men and women.”
The Ministry of Defence said in a statement: “The Nimrod R1 operated by 51 Squadron has a highly sophisticated and sensitive suite of systems used for reconnaissance and gathering electronic intelligence.
“However, due to operational security, we are unable to discuss its operations.”
Inayat Bunglawala, assistant secretary-general of the Muslim Council of Britain, expressed his shock at the report.
He said he was aware that some British Muslims travelled to Afghanistan to fight when hostilities began in 2001.
He had heard of no cases since then, but accepted it was “not beyond the bounds of possibility”, given that the conflict had lasted so long.
Mr Bunglawala said: “I do know that when the initial bombing was occurring in late 2001, there was a lot of sympathy for the Afghan people, who had endured so much.
“I am surprised if people are going now. I wasn’t surprised then, but I am surprised now.
“That’s the effect of the conflict having dragged on. We were told it would all be over in a few weeks, but the end is still not in sight.”
He urged British Muslims opposed to the war in Afghanistan to protest peacefully using the democratic means available in the UK.
“I don’t think it can be denied that our actions overseas have contributed to some British Muslims being radicalised,” he said.
“Our advice to youngsters is to campaign within the democratic framework here.
“Going to fight British soldiers in Afghanistan leaves them open to accusations, quite rightly, that they are betraying their own country.”