Perugia is a possible target of attack, the authorities say

Three Italian and two Turkish nationals were held in the raid focusing on the central university town of Perugia.

As part of the same investigation, nine other suspects were reportedly held across Europe - seven in Turkey and one each in Belgium and the Netherlands.

Italian police said they dismantled a Turkish cell that had carried out terrorist attacks in Turkey.

Italy's secret services have warned of an upsurge of radical Islamic activism in recent months and the risks that individuals or small groups, even those with no links to organised terror, could embark on attacks.

The country has been on a state of alert since the 11 March bombings in the Spanish capital, Madrid.

The interior ministry had identified Perugia - which has a university for foreigners - as a possible target of attack by militant Islamists.

Europe sweep

Perugia's public prosecutor had issued at least 14 arrest warrants.

The early morning operation targeted "crimes that have the aim of international terrorism," Perugia police said.

They said it succeeded in dismantling a cell of the outlawed Turkish Revolutionary People's Liberation Party-Front (DHKP-C).

The DHKP-C group admitted carrying out two suicide bomb attacks in Istanbul in September 2001 that killed three policemen and one Australian citizen and wounded 28 people, mostly police officers.

The illegal group, which aims to topple the Turkish government and replace it with a Marxist one, has carried out a series of other bombings since 2001.

One of the Turkish nationals held was said to have headed the cell - which was helped by local Italian anti-imperialist campaigners, Italian authorities say.

Among the Italians arrested is Moreno Pasquinelli, spokesman for the Anti-imperialist Camp - a group opposed to the US-led occupation of Iraq.

They had been gathering funds to finance the Iraqi resistance to the occupation.

"We support the armed struggle in Iraq. Our money is to help them, it doesn't matter to us if they use it buy weapons, Kalashnikovs, or medicines for people," Mr Pasquinelli told the BBC last year.

The group's website on Iraq has been taken down by the Perugia police.

Increased risk

On Wednesday, Italian investigators said they were widening their probe into a Moroccan man who blew himself up last Sunday, after they received a posthumous letter from the man, saying his suicide was in protest at the war in Iraq.

Milan's Duomo cathedral has been mentioned as an attack target

Thirty-five-year-old Moustafa Chauki filled his car with gas cylinders and set fire to it, outside a MacDonald's, in the northern city of Brescia.

In the letter he specified that he was not a member of al-Qaeda or any terrorist group, but was angry about the war in Iraq and blamed Italy for supporting it.

Italy has arrested several suspected Islamic militants recently - mainly in the north of the country.

Investigators say the area is home to Muslim groups with possible links to al-Qaeda.

In February, Italian police arrested three North Africans suspected of plotting to bomb Milan's metro and a cathedral in northern Italy.