World leaders mourned Pope John Paul on Saturday, many hailing him as a force for peace across the globe while others credited him with a major role in the fall of the Iron Curtain.

From Brazil to the Philippines, South Africa to Germany, Roman Catholics prayed, wept and hugged each other in grief when news flashed across the globe of the death of the Pope, who led the Church for 26 years -- the third-longest pontificate.

"The Catholic Church has lost its shepherd. The world has lost a champion of human freedom and a good and faithful servant of God has been called home," President Bush said at the White House with his wife Laura beside him.

"We're grateful to God for sending such a man ... a hero for the ages," said Bush, who went to war in Iraq despite the Pope's opposition but who as a Christian shared other views with him. He ordered US flags to fly at half-mast as a mark of

respect.

UN Secretary General Kofi Annan said the Pope was a man of peace. "He ... (was) extremely concerned about the world we lived in, and like me, he also felt that in war, all are losers." said Annan.

Lech Walesa, who led Poland's Solidarity movement which won power after a decade of struggle and hastened the collapse of the whole Soviet bloc, said Polish-born John Paul inspired the drive to end communismin Eastern Europe.

"(Without him) there would be no end of communism or at least much later and the end would have been bloody," Walesa said.

Former Soviet leader Mikhail Gorbachev said the Pope was "humanitarian number one on the planet." Russian President Vladimir Putin said John Paul's "spiritual and political legacy have been deservedly valued by humanity."

German Chancellor Gerhard Schroeder, whose country was once divided by the Iron Curtain, said: "By his efforts and through his impressive

personality, (the Pope) changed our world."

In the Pope's homeland, Poles wept and prayed in silence after his death, church bells tolled across the country and sirens wailed in the capital Warsaw.

"This is a terrible shock, I don't know what to say. He meant everything to us," said Maria Drapa, one of thousands who held a vigil in the Pope's home town of Wadowice.

In Madrid, several thousand people, mostly young, gathered in a square, holding candles, singing hymns and playing tambourines in front of pictures of the Pope. In Cologne, a heavily Catholic German city, hundreds packed its cathedral.

Israelis and Palestinians alike paid respects to the Pope, whose millennium pilgrimage of peace to the Holy Land stood in stark contrast to violence that has raged in the years since.

Bells tolled at the Church of the Nativity in Bethlehem, the traditional birthplace of Jesus, after news of his death.

Palestinian President Mahmoud Abbas described John Paul as "a great religious figure who devoted his life to defending the values of peace, freedom, justice and equality for all races and religions, as well as our people's right to independence."

Rabbi Marvin Hier, founder of the Simon Wiesenthal Center in Los Angeles, said: "No Pope did more for the Jews." On his Holy Land visit in March 2000, the Pope prayed at Jerusalem's Western Wall and asked forgiveness for Catholic sins against Jews after 2,000 years of Christian-Jewish hostility.

"There is a shattering difference between the Catholic church of 20 to 50 years ago to today," said Bobby Brown, the World Jewish Congress's Israel-based international director.

Church bells rang out for the Pope in communist Cuba as authorities allowed Catholics to mourn a man they praised for standing up to neoliberal capitalism. Cubans filled churches for services for the only pontiff to set foot on the island.