The PKK started as a Marxist-Leninist group demanding an independent homeland, but shed socialist ideology with the end of the Cold War and says it seeks some degree of self rule, similar to that of Spain's semiautonomous Catalonia region.

Arrested in 1999, PKK leader Abdullah Ocalan still enjoys a personality cult among sympathizers and is believed to send directives through lawyers from prison.

But the tight control that characterized the PKK eroded. In 2004, it dropped a unilateral cease-fire. Last year, a splinter operation called the Kurdistan Freedom Falcons bombed Turkish tourist resorts. An Iranian Kurd group affiliated with the PKK is fighting Iran.