Pope Francis has given his OK to pilgrimages to a Bosnian shrine where young people said the Virgin Mary appeared to them, but the Vatican cautioned on Sunday that the Church still hasn't ruled on the authenticity of the phenomenon, which has drawn millions of Catholic believers and the curious to the site.

Vatican spokesman Alessandro Gisotti said in a written statement that "the Holy Father has ruled that it's possible to organize pilgrimages to Medjugorje."

The decision, which could further boost tourism, was announced also by the Vatican's envoy to the local parish and by the papal nuncio in Sarajevo.

The shrine is 120 kilometers (75 miles) south of Sarajevo, the capital of predominantly Muslim Bosnia.

In 1981, during the papacy of the first pope from Eastern Europe, John Paul II, six youths said they witnessed apparitions of Mary.

Gisotti stressed that "care be taken to avoid interpreting these pilgrimages as authentication of the noted events, which still require examination by the Church."

"Thus it must be avoided that such pilgrimages create confusion or ambiguity regarding the doctrinal aspect," said the Vatican spokesman.

Last year a million people flocked to Medjugorje, where faithful kneel in prayer before a statue of Mary.

Gisotti offered this context for the pope's ruling. "Considering the notable flow of persons who go to Medjugorje and the abundant fruits of grace that have sprung from that, such a ruling fits into the special pastoral attention that the Holy Father has intended to give to that reality, aimed at encouraging and promoting the fruits of good."

The Vatican statement also emphasized that priests who organize the pilgrimages must be properly prepared, so that those who go to the shrine to celebrate Mass there avoid triggering any doctrinal confusions.

Since the apparitions were first cited, millions of Catholics have flocked to the site. But despite years of study, the Vatican has never declared the visions as authentic, unlike the phenomenon of apparitions of Mary at Fatima, Portugal, and Lourdes, France, two other immensely popular pilgrimage destinations.

Eldar Emric contributed from Sarajevo, Bosnia.