ANTI-TERRORIST police who arrested eight men yesterday in a series of armed raids believe that they may have thwarted the next wave of suicide bomb attacks on British and US forces in Iraq.

Three of the men were being held on suspicion of encouraging and financing al-Qaeda’s terrorist operations abroad and, it is believed, could have been involved in training and recruiting volunteers for suicide missions inside Iraq.

The other five, including Tahir Nasuf, 44, were arrested on immigration matters.Mr Nasuf had his assets frozen in February after the US Treasury alleged he was involved in a Muslim charity that was a front for a terrorist organisation linked to al-Qaeda.

At least one of the men being questioned, all of whom are Muslims from Libya, is understood to have travelled to Syria for training by Islamic extremists who have smuggled a number of young British-based militants across the border to fight under Abu Musab al-Zarqawi, al-Qaeda’s leader in Iraq, who has a $25 million bounty on his head.

Security sources say the brother of one of those arrested is believed to have been killed in Iraq. Two of those detained have been named on a UN website as having terrorist links, and the Treasury has frozen their assets in Britain.

What will concern John Reid, the Home Secretary, is that a number of these men have been granted asylum but are understood to have been using different identities and conflicting personal details, such as their dates of birth and addresses.

Senior police officers say that the operation was sanctioned before Mr Reid was appointed to his new job but he has been kept informed about developments. The raids are part of an investigation, codenamed Operation Hemlock, that has been under way for more than a year. The joint MI5 and police operation began before the July 7 attacks in London and yesterday’s raids were, according to a senior figure, “just the tip of the iceberg”, with many more arrests expected.

None of those held in Manchester, London and Merseyside is suspected of being involved in activities that posed a direct threat to Britain’s security.

Michael Todd, the Chief Constable of Greater Manchester, said: “We are talking about the facilitation of terrorism overseas. This could include funding, providing support and encouragement to terrorists. We are absolutely determined to make an impact, whether it is at home or abroad.”

A senior detective involved in Operation Hemlock told The Times that they had obtained a “rich pattern of intelligence”, all focusing on Iraq.

One of the major strands of the investigation is linked to the death early last year of Idris Bazis, 41, a French-Algerian who lived in Manchester and was killed in a suicide attack on US troops.

More than 500 police officers from five forces, MI5 agents and officers from the Immigration Service raided 18 properties under the Terrorism Act in an operation co-ordinated by Greater Manchester Police.

Twelve places were raided in Greater Manchester, where six men were detained. Police also searched three properties in the West Midlands and one each in Merseyside, Cleveland and London. One man was arrested in the Midlands and another in London.

Mr Nasuf, 44, was among five people who had their assets frozen by the Bank of England in February. This followed claims by the UN and the US Treasury that Mr Nasuf worked as a volunteer for the Sanabel charity, which they claim was a front for the Libyan Islamic Fighting Group, and was in turn allegedly linked to al-Qaeda.