VATICAN CITY - The Catholic Church has called for a global day of fasting and prayer on Saturday for peace in Syria and against any armed intervention, with Pope Francis scheduled to host a mass vigil on St Peter's Square.
The Argentine pope has called for a "cry for peace" from the world's 1.2 billion Catholics, Christians as a whole, believers from other faiths and atheists.
Syria's Sunni Muslim leader, Grand Mufti Ahmad Badreddin Hassoun, has called for Syrians to join in the prayers and the patriarch of Constantinople Bartholomew I, spiritual leader of the world's Orthodox, has said he is also backing the initiative.
A giant peace flag will also be raised in Assisi, the hometown of the patron saint of peace St Francis whose name the pope adopted when he was elected in March.
There has been a giant mobilisation of Catholic churches worldwide - through traditional homilies at mass as well as via social media - for the faithful to pray for peace and engage in some form of fasting.
The four-hour prayer vigil in the Vatican starts at 1700 GMT but there will be similar smaller initiatives around the world from Baghdad to Jerusalem, from Mumbai to Buenos Aires, from Washington DC to Beirut.
The pope's call is not unprecedented but unusual and experts have likened it to the global day of prayer instituted by late pope John Paul II following the September 11, 2001 attacks on the United States.
It has also been compared to impassioned calls for peace by John Paul II in the run-up to the Iraq war and a speech by another papal predecessor, Paul VI, against the Vietnam War at the United Nations.