The children released the solid white birds Sunday before tens of thousands of pilgrims in St. Peter's Square, only to watch on as a seagull swooped in and began to attack both birds, ANSA reported.
Not long after, a black crow also began pecking at the doves, Britain's The Mirror reported.
It wasn't clear whether the doves survived the attacks.
Just prior to the release of the birds, the Pope called for an end to violence in Ukraine.
"I am close to Ukraine in prayer, in particular to those who have lost their lives in recent days and to their families," Pope Francis said. "I hope that a constructive dialogue between the institutions and civil society can take place, that any resort to violence is avoided and that the spirit of peace and a search for the common good is in the hearts of all."