The U.K. sanctioned three cryptocurrency exchanges on Thursday as part of a package that includes 38 new designations aimed at financial networks it suspects are helping Russia evade sanctions.

The Foreign Office named Xeltox Enterprises, the Canadian-registered company behind crypto exchanges Cryptomus, Heleket and Certa Payments, as well as Kyrgyzstan-based TokenSpot. It also sanctioned payment platforms Processing KG, which operates VexPay, and Tsunami Payments, as well as Ulan Bukabaev, a director of Processing KG.

The government said two of the targeted businesses had processed or facilitated transactions involving A7, a Kremlin-backed network that operates ruble-pegged stablecoin A7A5 it says is used to bypass sanctions on…