The festivities, often mired in violence and bloodshed in the past, passed without major incidents, but police detained nearly 30 people in Istanbul.

Marking the arrival of spring, Newroz Day has become a platform for Kurds to demand broader rights and voice support for the outlawed Kurdistan Workers' Party (PKK), waging a bloody separatist campaign in the Kurdish-majority southeast.

The largest crowd gathered in Diyarbakir, the biggest city of the region, where some 3,000 officers were on duty and police helicopters overflew the packed festival venue.

Officials were not immediately available to provide an attendance figure, but estimates ranged from 200,000 to 400,000 people.

Demonstrators brandished posters of jailed PKK leader Abdullah Ocalan as songs praising the PKK blared from loudspeakers. Women clad in colourful traditional dresses danced and waved flags in the Kurdish colours of red, yellow and green.

"Democratic solution or democratic resistance," one banner read as hardliners chanted: "Blood for blood, we are with you Ocalan."

Speakers criticised Ankara over a faltering initiative to mend fences with the Kurds, which was announced last year but has produced little result so far.

Selahattin Demirtas, head of Turkey's main Kurdish political movement, the Peace and Democracy Party (BDP), slammed Ankara for branding the PKK a "terrorist" organisation and rejecting dialogue with the group.

"There are no terrorists, there is a people's movement and its leader," he said, referring to Ocalan, jailed for life in 1999.

In a message read out at the gathering, Ocalan accused Ankara of "flinching from a democratic solution" to the conflict.

Large crowds celebrated the day in other towns in the southeast as well as in Istanbul, home to a large Kurdish migrant community, where police detained 29 people, among them 17 minors, for chanting pro-PKK slogans and displaying rebel banners, Anatolia news agency reported.

In a statement issued Saturday, Prime Minister Recep Tayyip Erdogan appealed for reconciliation, saying the traditional Newroz bonfires should signify "the light of love, friendship and fraternity and not the fire of violence and hatred."

In August, his government announced plans to expand Kurdish freedoms in a bid to erode popular support for the PKK and end the insurgency, which has claimed some 45,000 lives since its outbreak in 1984.

But the initiative faltered in December when seven soldiers were killed in a PKK ambush and the constitutional court outlawed the BDP's predecessor for links to the PKK, sparking deadly protests and street violence.

Ankara says it remains committed to reform, but is yet to take concrete steps.

Erdogan's government has undertaken some measures to ease rampant poverty in the southeast and expand Kurdish cultural freedoms, winning notable popularity among Kurds.

Last year, the state broadcaster inaugurated a Kurdish-language television channel, a milestone in a country where speaking Kurdish was banned until the early 1990s.

Sceptics however argue ultimate peace cannot be achieved as long as Ankara insists on rejecting dialogue with the PKK.

Two people were killed in Newroz clashes between protestors and police in 2008 after celebrations were banned in several towns. The bloodiest Newroz was in 1992 when clashes across the southeast claimed about 50 lives.