The Turkish Kurd group PKK says it had nothing to do with a suicide bomb attack in Istanbul on Sunday in which 32 people were wounded.
The group has been the subject of media speculation over the blast.
But in a statement through a Kurdish news agency, it rejected that and also said it was extending a ceasefire until next year's elections.
The government has said it is too soon to conclude which group was behind the attack.
Police say the bomber was a young male. He detonated the bomb after trying to board a police bus in Taksim Square. Fifteen police were among those wounded.