Three Kurdish lawmakers suspected of ties to PKK rebel separatists were to be released from prison on Saturday, a day after two other Kurd parliamentarians were freed, a judicial source said.

Kemal Aktas, Selma Irmak and Faysal Sariyildiz would be freed "during the day" from prisons in Mardin and Diyarbakir, two cities in Kurdish-dominated southeastern Turkey, the source said.

The five lawmakers were released pending trial after Turkey's top court ruled that their long pre-trial detention violated their rights.

They are all members of the pro-Kurdish Peace and Democracy Party (BDP) who had been detained in 2010 over suspected links to the banned Kurdistan Workers' Party (PKK), which has waged an armed struggle for an independent Kurd state.

The BDP has long argued that court rulings blocking the release of jailed Kurdish MPs were politically-motivated and warned they would harm the fragile peace process between the Turkish state and the PKK.

The peace process stalled in September after Kurdish rebels announced they were suspending their retreat from Turkish soil, accusing the government of failing to deliver on promised reforms.

The PKK, which is blacklisted as a terrorist group by Ankara and its Western allies, launched an insurgency seeking self-rule in the southeast in 1984 that has claimed about 45,000 lives.