Turkish security forces detained the man and woman -- Miroslav Farkas and Marketa Vselichova -- in the southeastern Sirnak province that borders Syria and Iraq, the pro-government Sabah daily said.

It said this was the first time Turkey has detained foreigners suspected of working with the YPG.

In Prague, the Czech foreign ministry confirmed the arrest of the pair, saying they had been detained while crossing the border from Iraq into Turkey.

"The police seized documentation from them mentioning the YPG group," ministry spokeswoman Michaela Lagronova told AFP. "They were interrogated by the prosecutor and accused of belonging to the YPG."

She said the Czech authorities had first become aware of their arrest on November 13 and the pair were now jailed in Sirnak city.

"Until the start of their trial we have no chance to talk to them. We are in contact with their Turkish lawyer," she said, saying Prague was working for them to be deported home.

Sabah said they adopted the names Serxwebun Botan and Zelane Botan to fight with the YPG and also printed the identity pages of their Czech passports.

Czech press reports said Miroslav Farkas and Marketa Vselichova were aged 30 and 24 respectively.

The YPG is seen by Turkey as the Syrian arm of the outlawed Kurdistan Workers Party (PKK) which has waged an over three decade insurgency against the Turkish state.

But the United States works closely with the group as the best ground force in Syria to defeat Islamic State (IS) jihadists. Turkey's NATO allies do not regard the YPG as a terror organisation.

Several Western nationals are believed to have been killed while fighting with the group in recent months.

Vselichova, a student, had recently told Czech media in an interview that she was "fascinated by the fight for Kurds for their freedom".

"I have read many books on the issue and I ended up deciding to go there," she told the Dnes newspaper, saying she had already been to the region four times.

The Sabah report claimed the two Czechs had been trained by German special forces and the French foreign legion.

The arrests come as tension is rising between Turkey and the European Union over the scale of the crackdown in the wake of the July 15 failed coup.

Ankara has meanwhile accused EU states -- in particular Belgium and Germany -- of giving sanctuary to wanted PKK militants and turning a deaf ear to demands for their extradition.