A presidential decree published Saturday added cryptocurrency exchanges to a list of firms covered by Turkey's terror financing and money laundering.

The decision will take immediate effect and will make it easier for the financial watchdog to investigate digital-currency holdings, according to a presidential decree published in the Official Gazette on Saturday.

The move came after a ban on using cryptocurrencies for making payments, which was introduced in response to claims that such transactions are too risky, took effect in Turkey on Friday.

The presidential decree makes “crypto asset service providers” responsible for seeing their assets are not used illegally.

Turkish authorities last month launched fraud investigations into two cryptocurrency exchanges, Thodex and Vebitcoin.

Six suspects linked to the Thodex probe were jailed Friday pending trial.

The investigation into Thodex, which handled daily trades of hundreds of millions of dollars, initially led to the arrests of 83 people after customers complained of not being able to access their funds. Interpol issued a detention warrant for the firm's CEO on Turkey's behalf. Turks have been increasingly attracted by cryptocurrencies as protection against the decline of the lira and double-digit inflation.

The government plans to establish a central custodian bank to eliminate counterparty risk following the recent collapse of the Thodex and Vebitcoin exchanges, according to a senior official familiar with the plans.