The state security court in Turkey has commuted the death sentence of Kurdish rebel leader Abdullah Ocalan to life imprisonment.

The semi-official Anatolia news agency said Ocalan - the leader of the Kurdistan Workers' Party (PKK) - would serve out his life in prison with no chance of parole or amnesty.

The decision is a formality in line with Turkey's abolition of the death penalty in August to meet criteria for European Union entry.

The abolition - except in times of conflict - was part of a comprehensive package of human rights laws rushed through parliament.

Ocalan was arrested in Kenya and convicted of treason in 1999 for his role in the PKK's 16-year guerrilla war against the Turkish authorities.

More than 30,000 people were killed in the war, in the mainly Kurdish south-east of the country.

Clear signal

Ocalan is the sole inmate of an island prison off Istanbul.

The BBC's Tabitha Morgan says Ocalan's fate still arouses strong feelings, with many Turks still believing he should hang.

But the decision is a clear signal, our correspondent says, that Turkey is serious about implementing EU reforms and the government will be hoping that the international community will take note of its efforts.

There have been no executions in Turkey since 1984.