Imprisoned Kurdish rebel leader Abdullah Ocalan has renewed a call for his fighters to end their armed struggle against Turkey as part of efforts for a peaceful resolution of an insurgency that has killed tens of thousands since 1984.

In a message read Saturday to thousands celebrating a spring festival, Ocalan said the Kurdistan Workers' Party, or PKK, should hold a congress to take a decision to abandon arms.

Turkey has engaged in talks with Ocalan's group in a bid to end one the world's longest, bloodiest conflicts.

Ocalan announced a historic cease-fire to end hostilities during the spring festival, called Newroz, in 2013. Later, however, his group halted the withdrawal of fighters from Turkish territory, saying Turkey had not kept its promises.