Ministers have adopted a new language for declarations on Islamic terrorism.
In future, fanatics will be referred to as pursuing "anti-Islamic activity".
Home Secretary Jacqui Smith said that extremists were behaving contrary to their faith, rather than acting in the name of Islam.
Security officials believe that directly linking terrorism to Islam is inflammatory, and risks alienating mainstream Muslim opinion.
In her first major speech on radicalisation, Miss Smith repeatedly used the phrase "anti-Islamic".