"The president's office expresses its anger at the Turkish constitutional court's outlawing of the Democratic Society Party (DTP)," said a statement released by the office of the president of Iraq's autonomous Kurdish region, Massoud Barzani.

"But at the same time it welcomes the policy of opening up adopted by the Justice and Development Party (AKP) government," the statement added.

"It hopes that the constitutional court verdict will not halt that process and calls on all Turkish factions to commit themselves to a policy of reconciliation so that it can be a success."

Hundreds of people protested in the regional capital Arbil against the Turkish ban, with demonstrators waving flags of the rebel Kurdistan Workers' Party (PKK), which has led a deadly insurgency in southeastern Turkey since 1984.

The Turkish constitutional court outlawed the DTP on Friday on the grounds that it was linked to PKK.

The decision overshadowed an initiative announced by the AKP government in August to expand Kurdish freedoms and stoked fears of an escalation of the insurgency which has seen Turkish troops and warplanes attack rebel rear-bases inside Iraq.

Violent protests flared in Turkey's Kurdish-majority southeast following the court's decision, prompting police to use tear gas and water cannon against enraged demonstrators, who barricaded roads and lit fires in the streets.

The government's reform drive already faltered earlier this month when one person was killed in violent protests over claims that jailed PKK leader Abdullah Ocalan's prison conditions had deteriorated. The PKK responded by killing seven soldiers in an ambush in northern Turkey last week.

The European Union, which Turkey is seeking to join, voiced "concern" over the DTP's closure, urging reforms to align Turkish laws on political parties with EU norms.

But the bloc continues to blacklist the PKK as a terrorist organisation, as does the United States as well as Turkey.