A Romanian baby died after a baptism ceremony in which infants are immersed in holy water three times.
The 6-week-old infant was rushed to a hospital in cardiac arrest on Monday and died a few hours later, the autopsy revealing liquid in his lungs, Agence France-Presse reported.
The tragedy put pressure on the Orthodox Church to change baptism rules.
Prosecutors have opened a manslaughter investigation against the priest in the city of Suceava.
“The death of a newborn baby because of this practice is a huge tragedy,” said a message with an online petition for changes to the ritual. “This risk must be ruled out for the joy of baptism to triumph.”
By Thursday evening, the petition had gathered more than 56,000 signatures, according to AFP.
One person online denounced the “brutality” of the ritual and another blasted the “stubbornness of those who think that it is the will of God” to maintain it.
Local media outlets reported about several similar incidents in recent years.