LONDON, March 5 (Reuters) - Russia declared a partial ceasefire on Saturday to allow humanitarian corridors out of the Ukrainian cities of Mariupol and Volnovakha, Russia's defence ministry said.

"From 1000 am Moscow time (0700 GMT), the Russian side declares a ceasefire and the opening of humanitarian corridors to allow civilians to leave Mariupol and Volnovakha," Russian news agencies quoted the Russian defence ministry as saying.