A further four North Korean banks were blocked from the world’s primary financial messaging service on Thursday, as they were not in-line with the organization’s membership criteria.

The SWIFT (Society for Worldwide Interbank Financial Telecommunication) system allows banks and financial institutions to communicate about transactions and trades. But this month SWIFT has blocked seven DPRK banks from using its services.

The Belgium-based group barred three banks designated by the UN on March 9, and another four that were not included on UN or EU blacklists on Thursday.

“The DPRK banks remaining on the network are no longer compliant with SWIFT’s