KOSICE, Slovakia (Reuters) - Sixty-one hospitals in Ukraine are not operational because of attacks by Russian forces, Health Minister Viktor Lyashko said on Tuesday.

       "Terrorists from the aggressor country have put 61 hospitals out of action," he said on television, adding that the authorities were unable to deliver critical medical supplies to front-line communities because of a lack of "humanitarian corridors." Russia denies attacking civilian targets.

       (Reporting by Max Hunder, Writing by Alessandra Prentice, Editing by Timothy Heritage)