Pope Francis walks past a statue of the Virgin Mary prior to the start of a mass at the Sanctuary of Our Lady of Fatima Saturday, May 13, 2017, in Fatima, Portugal.
The tombs are located in the new shrine of Fatima, properly called Basilica of the Most Holy Trinity, built between 2004 and 2007. "In our day, too", the Pope said, "there is great need of prayer and of penance to implore the grace of conversion", and an end to the many wars and conflicts in the world today, "which disfigure the face of humanity".
He went on: "With Mary's protection, may we be for our world sentinels of the dawn, contemplating the true face of Jesus the Saviour, resplendent at Easter".
Pope Francis said on Saturday he was hopeful of finding common ground with US President Donald Trump at their upcoming Vatican meeting, despite the leaders being starkly at odds over issues from migration to climate change.
Lucia said the Virgin Mary also called for the "consecration" of Russian Federation, adding, "If my requests are heeded, Russian Federation will be converted and there will be peace; if not, she will spread her errors throughout the world, causing wars and persecutions of the Church".
In one of the six apparitions, Bacani said the Blessed Mother appeared as the Our Lady of Sorrows.
The children's visions 100 years ago is regarded as one of the most important events of the 20th-century Catholic Church.
Mass at the Archdiocese of Cebu's mother church, the monsignor appealed to the faithful to carry out the message of the Our Lady of Fatima.
"Don't think of yourselves simply as the recipients of charitable solidarity, but feel that you share fully in the Church's life and mission", he said.
"Yes we pray, but when we are asked to offer sacrifices we have second thoughts and apprehensions of doing it". Neither, he added, is she someone trying to restrain a vengeful God.
In Portugal, Pope Francis celebrated the Mass to commemorate the 100th anniversary of the apparition of Our Lady of Fatima.
The pope will officiate at Saturday's Mass for the canonization of seven-year-old Jacinta Marto and her brother Francisco, nine, who said that the Virgin Mary had appeared to them on May 13, 1917.
The Marto siblings died in the Spanish flu pandemic that swept Europe after the First World War. He drew a connection between the so-called Bishop in white, Our Lady dressed in white at Fatima, and the white garment that expresses the innocence of little children after their Baptism.
Francisco and Jacinta Marto are the youngest-ever saints who didn't die as martyrs.
But Lucia became a nun and lived to the ripe old age of 97, dying in 2005. Efforts to beatify her are also underway. The canonisation was something that wasn't planned from the beginning, because the process of the miracles was in progress but the all of a sudden the reports were all positive, and it was done - that's how the story was told - for me it was a very great joy. The figure, deemed the immaculate heart of Mary, called on the children to recite the rosary every day and to pray for the world. "I couldn't ask for better, so he has answered all my prayers", she said.
The alleged apparitions, seen only by the trio, were followed by odd phenomena in October 1917 when some 70,000 onlookers waiting for a sign of the Virgin are said to have seen the sun dancing in the sky.