Police are investigating whether a prosecution can be launched against an Islam militant who called for terror attacks in the UK.

Manchester-born Hassan Butt yesterday used a radio interview to claim he had recruited more than 200 British Muslims to fight for Afghan-istan's former Taliban regime, and said that many of them would be returning to the UK for "military action".

His comments were condemned by mainstream Muslim leaders, and Downing Street warned that the 22-year-old's claims should be treated with caution.

The Prime Minister's official spokesman said: "Attention-seeking does take many different forms. We have to be slightly careful in giving too much credibility to claims like this."

A Metropolitan Police spokesman said that the force was looking into the possibility of prosecuting Butt.

He said: "The Met is working closely with the Crown Prosecution Service to examine comments made on the radio today, to establish if any offences have been committed."

Speaking on BBC Radio 4's Today programme, Mr Butt said that some British volunteers had been "martyred" in Afghanistan, and that others were in Pakistan "organising operations".

He said: "If they do return (to Britain), I do believe they will take military action within Britain.

The targets would be "military and Government institutes, as well as individuals".

Downing Street said that there was "no evidence" to support Butt's claim that hundreds of British citizens had joined the Taliban.

Dr Ghayasuddin Siddiqui, leader of the Muslim Parliament of Great Britain, said that Butt was one of a small group of misguided young men who were using Islam as "a cover for their evil designs".

A spokesman for the al-Muhajiroun group, which Butt has claimed to represent, said he was no longer linked to the organisation and did not have its support.

Mr Butt said he was not concerned about any investigation into his activities, as he believed UK law enforcement agencies were "incompetent"