Priests and anti-abortion activists will hold a communal prayer Friday in a Sverdlovsk region forest where locals found 248 preserved fetuses discarded in plastic barrels.
A church official told Interfax that local clergy had chosen the prayer "For those innocently slain" to mark the occasion and that the prayer would be recited in front of the Babes of Bethlehem icon.
Anti-abortion activists from Yekaterinburg, the regional capital, Moscow and other cities are also planning to pray in the forest Friday, the news agency said.
Early last week, locals discovered the fetuses in a wooded area five kilometers from the Yekaterinburg-Nizhny Tagil highway.
Attached to the fetuses, which had been preserved using formaldehyde, were tags containing surnames and numbers.
Police believe that the numbers indicate the hospital wards where the women who produced them had been patients and that one or more of the four nearby hospitals are responsible.
Church officials have said that the dumping of the fetuses reflects the degradation of modern society.