GENEVA (Reuters) - The U.N. human rights office (OHCHR) said on Monday it had confirmed the deaths of at least 636 civilians in Ukraine through to March 13, including 46 children.

       The actual toll is likely much higher, it said, since there have been delays receiving and corroborating reports from places with intense hostilities such as Kharkiv and Mariupol.

       OHCHR has some 50 staff members involved with human rights monitoring in the country.

       (Reporting by Emma Farge; Editing by Jon Boyle)