ISTANBUL (AFP) - Turkish authorities on Wednesday arrested six suspected members of the Islamic State in Iraq and Syria (ISIS) extremist group on suspicion of trying to illegally mint coins for use in areas controlled by the extremists in Syria.

Police in the southeastern region of Gaziantep on the border with Syria also seized coin punches, presses and other coin-making equipment, the official Anatolia news agency said, quoting a statement by the regional governor's office.

The regional police force issued a picture of the sophisticated equipment piled up in front of the police force's flag.

According to Turkish media reports, 56 coins in four different sizes were seized.

Another picture showed a punch to produce a coin with Arabic writing on one side and a picture of the world on the other.

There have been reports that ISIS is keen to impose its own currency in the areas it controls in Syria to free itself from the global financial system.

Acting on a tip-off, Turkish police raided the would-be mint in the town of Sahinbey just south of Gaziantep city.

The suspects, who include foreigners of unspecified nationality, were sent to court after being detained and remanded in custody ahead of trial, Anatolia added.

Turkey has been under pressure from its Western partners to crack down on the activities of ISIS militants inside the country and stop extremists from crossing into neighbouring Syria.

The authorities have arrested hundreds of foreign militants in the last months and Ankara says it is doing all it can to secure its borders and maintain security.