In a major step toward ending one of the world’s longest, bloodiest insurgencies, the Kurds’ jailed rebel leader called Thursday for a “new era” of peace that includes an immediate cease-fire and the withdrawal of thousands of his fighters from Turkey.

Abdullah Ocalan’s rebel group, the Kurdistan Workers’ Party, or PKK, has been waging a nearly 30-year battle against the Turkish government, seeking autonomy and greater rights. The fight has killed tens of thousands of people and the group is considered a terrorist organization by Turkey and its Western allies, including the United States.

The Turkish government reacted cautiously but Ocalan’s announcement at a Kurdish spring festival was met with joy from the hundreds of thousands who gathered to hear it in Diyarbakir, the largest city in Turkey’s mainly Kurdish southeast.

“We have reached the point where the guns must be silenced and where ideas must speak. A new era has started, where politics, not guns, are at the forefront,” Ocalan said in a call from jail relayed by pro-Kurdish legislators in both Kurdish and Turkish.

“A door is opening from the armed struggle toward the democratic struggle,” Ocalan said. “This is not an end. This is a new start.”

“We have reached the stage where our armed elements need to retreat beyond the border,” his message added.

People in the sprawling crowd sang, danced and waved rebel flags or banners with images of Ocalan. They appeared cheered at the prospect of an end to the conflict that has dominated the southeast for so long.

“Ocalan has paved the way for a historic peace process,” Mesut Yegin of Istanbul’s Sehir University said. “He has declared in no uncertain terms that the era of an armed struggle is ending.”

“But the total laying down of arms will depend on steps the government will take,” Yegin added.

Turkey announced in December that it was talking to Ocalan with the aim of persuading the PKK to disarm.

Despite his 14-year incarceration in a prison island off Istanbul, Ocalan still wields great power over his rebel group. PKK commanders based in northern Iraq have declared support for the peace initiative and Kurdish fighters in Turkey were expected to heed Ocalan’s call and retreat to northern Iraq.

Earlier this month, the rebels released eight Turkish soldiers and officials they had been holding captive in response to a request by Ocalan.

Nevertheless, Turkish officials sounded a note of caution Thursday.

“I see (the call) as a positive development, but it is its implementation that is important,” Prime Minister Recep Tayyip Erdogan said during a visit to the Netherlands. “We need to see to what extent (the rebels) respond to it.”

He added that Turkish security forces would cease operations against the rebels after the PKK fighters withdraw.

The Turkish leader also lamented the fact that no Turkish flag was flown at the festivities, calling it a “provocative act” contrary to the spirit of Ocalan’s message of unity.

Kurds make up an estimated 20 percent of Turkey’s population of 75 million. The rebels took up arms in 1984 to fight for Kurdish independence, but later revised that goal to autonomy in southeastern Turkey. The group frequently launched attacks on Turkey from bases in northern Iraq.