International payment systems Master Card and Visa Friday stopped service to clients of banks placed under US sanctions Thursday. Both blocked Rossiya Bank, which holds the private account of President Vladimir Putin. Master Card suspended service to another six Russian banks, and Visa cut ties to another three. Timur Batyrev, the head of the national payment system department at the Central Bank of Russia said the blockade came without warning. "The management of Rossiya understands the difficulties of clients in the current situation and will do all it can to solve them," the bank said in a statement.