A Finnish embassy official in Ankara named her as Kiristina Koivunen and said they did not know why she was detained Friday as she left the city of Van.

She had arrived in Turkey two weeks ago.

The embassy has contacted the Turkish foreign ministry for clarification and hopes to get some information next week, the official said, speaking on condition of anonymity.

Koivunen will be flown to Istanbul to be deported later Saturday, the official said.

Security sources said she was being expelled becasue the Turkish interior ministry had banned her from entering the country, but it was not immediately clear why.

Local sources said Koivunen, from Helsinki University, wrote articles in a Finnish newspaper on the separatist Kurdistan Workers' Party (PKK), which has been fighting the Ankara government since 1984.

More than 37,000 people have been killed since the PKK, classified as a terrorist group by Turkey and much of the international community, took up arms for self-rule in Turkey's mainly Kurdish east and southeast.

The PKK proclaimed a unilateral ceasefire from October 1, saying it hoped this would pave the way for a dialogue to resolve the conflict.

The truce, like the previous ones called by the rebel group, was rejected by Turkey, but fighting has decreased markedly since then.