Pope Francis, who often laments current persecutions of Christians, has given the Catholic Church 35 new saints, nearly all of them martyrs, from past centuries.

The latest saints were proclaimed Sunday during a Mass celebrated by Francis in St. Peter's Square.

Thirty martyrs, including priests and lay persons, suffered anti-Catholic persecution in 1645 at the hands of Dutch Calvinists in Brazil, while three children, indigenous persons in 16th-century Mexico, were martyred for embracing the Catholic faith and refusing to return to their ancient conditions.

The other two new saints are a 20th-century priest from Spain and an Italian priest who died in 1739.

Since becoming pontiff in 2013, Francis has repeatedly paid tribute to Christians suffering or even dying for their faith in current times, especially in the Middle East.

Up until July, there were three paths to canonisation: dying for the faith (or martyrdom), by living a life of "heroic virtue", like Mother Theresa or in "exceptional cases". But Pope Francis declared a fourth path to becoming a saint: following in the footsteps of Jesus and giving up your life for another person.