DIYARBAKIR, Turkey: A Turkish court released on Tuesday 10 pro-Kurdish politicians who were among hundreds, possibly thousands of people on trial accused of ties to the outlawed Kurdistan Workers' Party (PKK).

The court in the southeastern city of Diyarbakir freed the politicians on the grounds that the time they spent in custody had now exceeded any prison term they would serve if convicted, court sources told AFP.

Turkish authorities first launched a major campaign of arrests in 2009 against the Union of Kurdistan Communities (KCK) which is considered a terrorist organisation and an urban wing of the PKK.

Critics of the crackdown say the number of people arrested pending trial in the KCK case tops 3,500 while official figures from late 2011 say over 600 people had been arrested.

Tuesday's decision comes amid peace talks between the state and jailed PKK chief Abdullah Ocalan to negotiate an end to the Kurdish insurgency which has left 45,000 people dead since the PKK took up arms in 1984.

Nearly 1,000 more Kurdish prisoners are expected to be freed after parliament approves a new set of laws being drawn up by the government to bring its widely criticised anti-terrorism legislation in line with European standards.

Turkey has faced international criticism over lengthy pre-trial detentions of suspects -- including journalists, academics, activists, lawyers and politicians -- on terrorism charges.