DIYARBAKIR, Turkey: A Turkish court on Thursday sentenced to prison 40 Kurds for ties to the outlawed Kurdistan Workers' Party (PKK), the first verdict to come in a massive trial involving hundreds of suspects.

The court in Diyarbakir in southeast Turkey handed down jail terms ranging from three months to 17 years for membership in the Union of Kurdistan Communities (KCK), branded by authorities as a "terrorist organisation" and an urban wing of the Kurdish rebels.

The defendants were arrested in 2009 in the Kurdish-majority city of Sirnak in the southeast as part of a wider crackdown against the KCK.

Since then, 700 people have been arrested pending trial over alleged links to the KCK, according to government figures, although critics claim the number tops 3,500.

Thursday's verdict is the first in the huge trial where lawyers, politicians and journalists stand accused of KCK membership as related new cases keep piling up across the country.

Ankara says the KCK wants to replace Turkish government institutions in Kurdish-majority southeastern Anatolia with its own political structures.

The ruling comes at a time when Turkish officials acknowledge negotiations between intelligence services and Abdullah Ocalan, the jailed leader of the PKK, to end the nearly three-decade long insurgency.

"The intelligence services are in talks with him," Yalcin Akdogan, Prime Minister Recep Tayyip Erdogan's top political advisor said in televised remarks on Monday.

"The goal is the disarmament of the PKK.... The government supports any dialogue to this end that could result in a halt to violence," Akdogan said.

Ankara initiated clandestine peace talks with prominent rebel figures in 2009 but they failed, leading to an escalation of violence in Turkey, where some 45,000 people, most of them Kurds, have been killed since the conflict began.