David Willey: Kurdish supporters in Rome have threatened bloodshed

And for the first time, the United States has intervened in the dispute, saying that PKK leader Abdullah Ocalan should be sent to Turkey for trial.

The Turkish Prime Minister, Mesut Yilmaz, warned Italy that it will have to suffer the consequences if it fails to extradite the rebel leader, who is currently in custody in Rome.

Italy's response to the extradition request, he told the Turkish Parliament, will be a test of its commitment to combat terrorism.

Abdullah Ocalan: Turkey's most wanted man

"If it does not pass this test successfully it will become an accomplice to all the murders [the PKK rebels] have committed until now," Mr Yilmaz said.

The Italian Prime Minister Massimo D'Alema called a special news conference to respond to the statements in Ankara.

"Italy will not be subjected to totally unjustifiable intimidation," Mr D'Alema told reporters.

"Turkey is making a mistake ... Italy does not justify terrorism and does not intend in any way to be an accomplice [to terrorism]," he said.

He repeated that Mr Ocalan's extradition process would undergo the normal legal procedures.

Correspondents say Mr Ocalan's extadition to Turkey is unlikely, as, under the constitution, Italy cannot extradite a suspect to a country where the death penalty is in force.

Even if Turkey abolishes capital punishment, as the government in Ankara has suggested, officials in Italy's governing centre-left coalition have spoken in favour of granting the rebel leader political asylum.

Arrest but no extradition

Mr Ocalan is wanted in Turkey in connection with some 30,000 deaths attributed to the PKK during the organisation's 14-year campaign for Kurdish independence.

Turkish women with pictures of killed soldiers - the PKK's campaign claimed some 30,000 lives

He was arrested on international warrants - issued by Turkey and Germany - last Thursday at Rome's airport as soon as he stepped off a flight, but his request for political asylum is still being considered by the Italian authorities.

According to an Italian newspaper Mr Ocalan also claimed that the PKK had given up terrorism, and was ready for a peace accord.

"My presence here [in Rome] testifies to a change in the strategy of the Kurdish national movement," he was quoted as saying.

The BBC correspondent in Ankara, Chris Morris, says that this is a turning point in the struggle between the Turkish state and the PKK.

It is not yet clear who will emerge with an advantage but Turkey is increasingly worried that Mr Ocalan could be on the verge of a political breakthrough in Europe.

US supports extradition

The United States government has cast doubt on Mr Ocalan's pledge to renounce terrorism.

State Department spokesman James Rubin said that Mr Ocalan had made similar pledges many times in the past only to go back on his promise each time.

"We hope a way will be found to extradite him" - James Rubin

Mr Rubin expressed hope that Italian officials will eventually find a way to extradite him to Turkey.

"The vast majority of the terrorist acts committed by this man was against Turkish citizens on Turkish soil," Mr Rubin said.

Germany, however, which also has an outstanding warrant for Mr Ocalan on terrorism-related charges, will not ask for his extradition.

"[Mr Ocalan is] a matter for Italy," German Foreign Minister Joschka Fischer was quoted as saying.