Pope John Paul has celebrated his 25th Christmas Midnight Mass in the Vatican with calls for peace.

The Pope did not directly mention the threat of war against Iraq, but said the birth of Jesus remained a sign of peace for those suffering from conflicts of every kind.

Jesus is born for a humanity... yearning for hope Pope John Paul

The BBC Rome correspondent, David Willey, says the pontiff is expected to refer more directly to a possible conflict with Iraq in his traditional message on Christmas Day.

In recent days, senior Vatican officials have made clear the opposition to any war against Iraq, saying it would be "unjust".

The pontiff's homily comes in the closing days of a year which has seen mounting concern over the state of the ailing 82-year-old's health.

Silent vigil

Delivering his Christmas Midnight Mass homily at the Vatican, the Pope said the Nativity signified "God's merciful love" for the poor and oppressed, for sinners, for those who felt lonely and abandoned.

Christ's message remained valid for "those suffering from conflicts of every kind", the head of the Roman Catholic Church said.

"The centuries and the millennia pass, but the sign remains, and it remains valid for us too - the men and women of the third millennium."

Up to one billion Catholics across the world are marking Christmas

"It is a sign of hope for the whole human family; a sign of peace for those suffering from conflicts of every kind; a sign of freedom for the poor and oppressed; a sign of mercy for those caught up in the vicious circle of sin; a sign of love and consolation for those who feel lonely and abandoned.

"A small and fragile sign, a humble and quiet sign, but one filled with the power of God who out of love became man."

Up to 10,000 Roman Catholics gathered in Saint Peter's Basilica or outside to hear the homily.

Earlier the Pope appeared at his studio window above the square to light a candle in a silent vigil for peace.

Festive crowds have been listening to children's choirs and bagpipers in the square or visiting the Nativity creche and the Christmas Tree - this year a gift from Croatia.

War 'unjust'

While the theme of Iraq was absent by name from the pontiff's homily, it dominates the front page of the Christmas Day editions of the Vatican newspaper.

"While the clouds of war lengthen, the minds and hearts of men in all continents are drawn to Christmas," L'Osservatore Romano writes.

[War on Iraq] might unleash some sort of anti-Christian and anti-Western crusade Archbishop Jean-Louis Tauran Vatican foreign minister

The Vatican's former envoy to the United Nations, Archbishop Renato Martino, told reports only last week that a war against Iraq as threatened by the United States and Britain could not be "just".

Vatican officials have contrasted the situation over Iraq with the US-led war against terror after the 11 September 2001 attacks on America, which, they argue, was justified.

But Archbishop Martino, who is also the prefect of the Vatican's Council for Justice and Peace, said that a preventive war against Saddam Hussein was a "war of aggression" and therefore not a "just war".

The Vatican's Foreign Minister, Archbishop Jean-Louis Tauran, also warned that attacking Iraq could "unleash some sort of anti-Christian and anti-Western Crusade".

"It is sad to see the everyday use of armed violence according to a perverse logic that opposes terrorism to a crescendo of punitive expeditions that destroy any peace proposal and effort," he added.