In a harsh warning over its suspected ties, Turkish Prime Minister Recep Tayyip Erdogan ruled out any dialogue with the Democratic Society party (DTP) until it openly condemns the outlawed Kurdistan Workers' Party (PKK).

"First, you should come out and declare that the PKK terrorist organization is a terrorist organization," he said in comments directed to the DTP but made Tuesday before lawmakers from his Justice and Development Party (AKP). "Then we can speak."

Ahmet Turk, a veteran Kurdish politician and co-chair of the DTP, said he was upset that Erdogan would invite leaders of the radical Palestinian organisation Hamas to Ankara but at the same time refuse to meet "a legal party" such as the DTP.

Turkish authorities say the riots that claimed 15 lives in the past week were orchestrated in part by PKK chief Abdullah Ocalan from the prison island of Imrali where he has been serving a life sentence in solitary confinement since 1999.

Officials believe the PKK -- blacklisted as a terror group by Turkey, the United States and the European Union -- continues to fan unrest in a bid to position itself as an indispensable interlocutor in future negotiations.

Ankara categorically refuses any talks with the group.

Authorities also accused the DTP of toeing the PKK line during the unrest, which began in the southeast and spread to Istanbul, by repeating the banned organization's appeal for civil disobedience.

During the unrest DTP officials were accused of colluding with rioters, urging shopkeepers to close their shutters, and calling on Kurds to resist the security forces in the southeast, the theatre of long-running fighting between PKK rebels and the army.

The clashes, which left hundreds injured and saw hundreds of others detained, were the most serious urban disturbances to hit the region since the PKK called off a five-year unilateral truce in June 2004.

Like the series of pro-Kurdish parties that preceded it, the DTP could find itself facing a possible ban as a result of recent statements by DTP officials, terrorism expert Ercan Citliogu said.

"The organic link between the PKK and the DTP was confirmed during the protests," he told AFP. "I would not be surprised if legal steps were taken soon to ban the party."

He said the DTP had failed to distance itself from the ideology of Ocalan and the PKK.

The DTP, which is not represented in parliament, was founded in 2004 by Kurdish former lawmakers -- including rights activist Leyla Zana, who spent a decade in jail for links with the PKK -- saying they favour dialogue between Turks and Kurds.

It succeeded the DEHAP, which disbanded as it faced a possible ban for alleged links with PKK rebels and suspected electoral fraud in the 2002 parliamentary vote.

Metin Tekce, a DTP member and the mayor of Hakkari, on the border with Iraq and Iran, drew strong criticism recently when he said the PKK was not a terrorist organisation.

Osman Baydemir, the popular DTP mayor of Diyarbakir, the biggest city of the southeast, is under judicial investigation for "praising terrorism" when he hailed the "courage" of young rioters there as he tried to reason with them.

More than 37,000 people have died in fighting in southeastern Turkey between the army and the PKK since it took up arms for Kurdish independence in 1984.