The People’s Bank of China (PBOC) said it had summoned several major banks and payment companies to call on them to take tougher action over the trading of cryptocurrencies.

In a statement, the PBOC said banks were told not to provide products or services such as trading, clearing and settlement for cryptocurrency transactions.

The Agricultural Bank of China, the nation’s third-largest lender by assets, said it would follow the guidance from the PBOC.

It also said it would conduct due diligence on clients to root out illegal activities involving cryptocurrency mining and transactions.

China’s Postal Savings Bank also announced it would not facilitate any cryptocurrency transactions.