KYIV (Reuters) - Ukraine has appealed to Medecins Sans Frontieres (Doctors Without Borders) to help evacuate fighters holed up in the vast Azovstal steel works in Mariupol that is surrounded by Russian forces.

       Ukraine's Ministry for the Reintegration of the Temporarily Occupied Territories said it had written to the medical charity and asked it to assess the fighter's physical and mental condition, collect evidence of the conditions they are in and provide medical assistance to "Ukrainians whose human rights have been violated by the Russian federation."

       Russia denies targeting civilians and has urged the fighters in the sprawling plant to surrender.

       (Reporting by Natalia Zinets, Editing by Timothy Heritage)