Ankara lists Ocalan's separatist Kurdistan Workers' Party (PKK) as a terrorist group and rejects dialogue with the rebels in efforts to end their bloody 26-year insurgency in the Kurdish-majority southeast.

"We, as the government, will never sit at the table and have talks with a terrorist organisation or its representatives. Such a thing has never happened," Prime Minsiter Recep Tayyip Erdogan said in a television interview late Monday, according to Anatolia.

He added however that, "If some contacts are required... the state will do that... These two must not be confused."

"The state, for instance, has an intelligence agency... to unlock, resolve certain issues. It does that (having contacts), but the government can never recognise (the PKK) as an interlocutor and sit at the table," he said.

The PKK said Monday a truce it declared from August 13 to September 20 was the result of "dialogue between our leader (Ocalan) and competent authorities acting in the name of the Turkish state with the knowledge of the government."

The government has come under opposition fire for "bargaining" with the PKK in a bid to lure Kurdish support at an upcoming referendum on constitutional amendments.

The truce, which covers the holy Muslim month of Ramadan and the September 12 referendum, was declared after a dramatic rise in PKK violence since May 31 when Ocalan said he was abandoning efforts to seek dialogue with Ankara.

Although behind bars since 1999 on a life sentence, Ocalan retains influence over the PKK, often issuing guidelines to the rebels through his lawyers.

The PKK and Turkey's main Kurdish political movement, the Peace and Democracy Party, demand that Ankara recognise the Kurds as a distinct element of the country's population and grant them autonomy.

The PKK took up arms in 1984, sparking a conflict that has claimed some 45,000 lives.