Young British Muslims who fight for the Taliban could face treason charges, a government minister warned on Thursday.

Speaking in the House of Lords, Home Office minister Lord Rooker cautioned British citizens or residents that "it was totally unacceptable to take up arms against British soldiers and allies".

"People should be aware that criminal sanctions will apply including the use of the Terrorism Act 2000 or the Treason Act 1351 depending on the circumstances of the case," he said.

Following media reports that UK citizens had been killed in Afghanistan while fighting for the Taliban and that extremist Muslim groups were recruiting in UK cities, Rooker pledged to peers that the legal authorities, the police and security services were "at work on this issue on the streets of Britain".

"They will be rooted out," he promised. "The idea that a British citizen will go abroad to fight for a government that denies women the right to work or an education is nothing short of a scandal, and that is using the most moderate language which I dare use as a minister."

The Home Office minister also urged anyone thinking of joining the Taliban to have "a chat with the many thousands of people from Afghanistan who are seeking refugee status in the UK at the moment...Who will let them know what the facts are."

But Rooker told the Lords that he knew of no arrests for related offences and that "there is scant evidence of the allegations that people have left this country to fight".

"Evidence is in short supply. Evidence is needed if there are to be prosecutions," he said.

The government minister also warned the media that "it was wrong to compartmentalise people". "We don't believe that we have any 'enemy within' in terms of listing a subject group and it is outrageous for people to write in those terms about various minorities in the country," he said.

And Rooker paid tribute to Muslim servicemen who had fought to defend Britain.

"There have been people from all religions and all cultures who have defended and come to the assistance of this country in times of need," he said.