The Vatican is close to making a ruling on the alleged apparitions of the Madonna in the Bosnian town of Medjugorje, one of the most controversial cases in the Roman Catholic Church, Pope Francis said on Saturday.

Six children first reported visions of the Virgin Mary in the once obscure town in 1981. It has since become a major pilgrimage site, giving many a new sense of spirituality and locals a steady source of much-needed revenue.

Many others, however, believe the alleged apparitions are a hoax.

While flying back to Rome from his visit to Sarajevo, the pope was asked about the status of a Vatican investigation into the alleged apparitions, which have divided the Catholic Church.

"We are about to make decisions and then they will be communicated," he said, adding that he recently received a long study by a Vatican commission and that the case was now before the Holy See's doctrinal department, the Congregation for the Doctrine of the Faith.

In recent years, the town has experienced a building boom of hotels and shops catering to pilgrims.

Some of the alleged visionaries, now adults, say they still experience apparitions every day and that the Madonna has told them secrets.

The Church has so far been cautious, saying dioceses should not organise official pilgrimages to the town. But many parish groups are among the more than a million visitors a year to the site.