London - Britain is home to 35,000 fanatical Islamists, and 3,000 are ‘worrying' MI5 security chiefs, a top anti-terrorism official has said. The UK has more radicalised Muslims than any other European country, EU counter-terrorism co-ordinator Gilles de Kerchove revealed. He also warned how Isis will attempt a cyberattack on nuclear power stations or air traffic control systems within five years, possibly by paying Russian hackers to break into vital computer systems. The official, who has been in his post since 2007, said: ‘The United Kingdom has identified 20,000 to 35,000 radicals. ‘Of these, 3,000 are worrying for MI5, and of those 500 are under constant and special attention.