MADRID (AP) — Spanish and French authorities on Tuesday arrested 23 alleged members of the Kurdistan Workers Party on suspicion they engaged in extortion to finance the operations of the rebel group seeking autonomy for Turkey's Kurds, officials said.

Six of the suspects were detained in Madrid, Barcelona and the southern city of Murcia, Spain's Interior Ministry said in a statement. Authorities also raided seven places linked to the suspects, who are accused of levying a "revolutionary tax" on fellow Kurds in an extortion scheme aimed at buying arms and explosives for use in terror attacks in Turkey, the statement said.

In France, Agnes Thibault-Lecuivre, a spokeswoman for the Paris prosecutors' office, said 17 people had been arrested by Tuesday evening. They were detained in the southwestern cities of Bordeaux and Toulouse.

She said the arrests, involving counterterrorism police, were the first stemming from a preliminary French investigation opened in March into alleged extortion to help finance the Kurdish rebel group.

French authorities also seized at least €28,000 ($37,600) during their operation, she said.

The conflict in Turkey between the group, also known as the PKK, and government forces has claimed tens of thousands of lives since 1984 when the rebels took up arms with the aim of gaining autonomy in Turkey's mainly Kurdish southeast. The PKK is considered a terrorist organization by the European Union and the United States.