Britain on Tuesday sent in a former counter-terror chief to investigate claims of an Islamist plot to take over schools in the second city of Birmingham.
The education ministry has appointed Peter Clarke, who headed the police investigation into the July 7, 2005 London bombings, to conduct a probe into the allegations.
The former head of Scotland Yard's Counter Terrorism Command will "analyse evidence of extremist infiltration" in Birmingham schools, the ministry said.
However, the appointment drew immediate criticism from the local police chief, who said people would inevitably draw "unwarranted conclusions".
Concerns about how some schools in the central English city were being run first emerged last year in a leaked anonymous letter which outlined how to implement what it called Operation Trojan Horse -- the takeover of schools by hardline Muslims.
The letter, which credited the operation with forcing a change of leadership at four schools, gave instructions on ousting and replacing uncooperative headteachers and school governors.
"I am extremely concerned by the allegations made in connection to a number of schools in Birmingham," said Education Secretary Michael Gove.
"These allegations need either to be substantiated and firm action taken, or to be shown to be baseless.
"Peter Clarke brings a wealth of relevant skills and experience, and is very well placed to lead a fair and thorough assessment of the evidence.
"No pupils should be exposed to extremist views or radicalisation while at school."
Gove has already sent inspectors to 15 schools, while Birmingham City Council is investigating 25, having received more than 200 complaints.
Since the letter emerged, whistleblowers including former staff have come forward, making claims that boys and girls were segregated in classrooms and assemblies, sex education was banned and non-Muslim staff were bullied.
Birmingham has a large Muslim community. Some 22 percent of the city's 1.1 million residents identified themselves as such in the 2011 census.
The move to appoint Clarke was blasted by local police officials.
"This is a desperately unfortunate appointment," said West Midlands Chief Constable Chris Sims.
"Peter Clarke has many qualities but people will inevitably draw unwarranted conclusions from his former role as national co-ordinator for counter-terrorism."
Bob Jones, the elected police and crime commissioner overseeing the West Midlands force, said: "This appointment gives the clear impression that the issues around Trojan Horse are predominantly around counter-terrorism issues."
Clarke "lacks the relevant experience in educational governance issues that are key to this investigation," he said.
The allegations focus on a category of schools known as academies. Established from 2000 onwards, they are state-funded but are self-governing and independent of local authority control.