This is because the risks are too high for Swiss bank UBS, which recently took over its rival in a government-brokered merger.
It is not clear exactly which Russians are affected, the paper wroteExternal link. However, they are said to be primarily Russian offshore clients: clients with a Russian passport who live abroad and who are currently serviced by Credit Suisse from Switzerland on a cross-border basis.
https://www.swissinfo.ch/eng/business/ubs-drops-credit-suisse-s-russian-clients/48699962