(Reuters) - Russia has opened "humanitarian corridors" so people can be evacuated from Kyiv and four other Ukrainian cities: Cherhihiv, Sumy, Kharkiv and Mariupol, the Interfax news agency quoted the Russian defence ministry as saying on Tuesday.

       The defence ministry added that Russian forces in Ukraine had introduced a "silent regime" from 0700 GMT, Interfax reported.

       (Reporting by Reuters)