Turkish air strikes killed eight civilians in Syria's Kurdish-held northeast Monday, a war monitor and local media said, as Ankara launched operations in Iraq and Syria following deadly attacks on its soldiers.

On Saturday, Turkey announced a new wave of air strikes in retaliation for two separate attacks on its bases in northern Iraq that killed 12 soldiers, which Ankara blamed on Kurdish militants.

Eight civilians were killed in strikes on Monday, said the Syrian Observatory for Human Rights, revising an earlier toll of six deaths.

Pope Francis on Monday deplored the desperate humanitarian situation of Palestinians in Gaza and called for an immediate ceasefire and the freeing of hostages in his Christmas message.

"My heart grieves for the victims of the abominable attack of 7 October, and I reiterate my urgent appeal for the liberation of those still being held hostage," the 87-year-old said in his traditional Urbi et Orbi message.

On a countryside road in battle-ravaged Sudan, the hum of a passing vehicle turns villagers' blood cold, fearing the arrival of paramilitaries plundering their way south in their war against the army.

"They've created a state of total panic," said Rabab, who lives in a village north of Wad Madani, the Al-Jazira state capital and latest site of fierce battles between the army and the paramilitary Rapid Support Forces (RSF).

Israel on Monday said it was "intensifying the fighting" against Hamas in Gaza, where relentless strikes across the Palestinian territory exacerbated the dire conditions for civilians in the war's 12th week.

The conflict has heightened tensions across the Middle East where Iran -- which supports Hamas -- on Monday accused Israel of killing a senior Revolutionary Guards general in Syria and vowed revenge.

An unusual silence fell over the streets of Zababdeh, a Palestinian village that is home to one of the biggest Christian communities in the occupied West Bank.

On any other Christmas Day, Palestinian Christians would have flocked from surrounding towns to enjoy the fairy lights and a festive market in the village of some 5,000 people.

But as the war rages in Gaza and violence also surges in the West Bank, the Christian community here is in no mood to celebrate Christmas on Monday.

Sadness over the war in Gaza subdued the holiday cheer in Bethlehem on Christmas Eve, when the biblical town would usually be decked out in festive finery.

There was no revelry on Sunday, with few worshippers or tourists on the streets of the Palestinian town in the occupied West Bank, which according to Christian tradition was the birthplace of Jesus Christ.

Celebrations in the Holy Land have mostly been cancelled in solidarity with the people of Gaza, who are living through the deadliest war ever to engulf the besieged Palestinian territory.

Palestinians said they felt "no joy" this Christmas as Israel bombed Gaza on Monday, with no end in sight to the war that Hamas says has claimed more than 20,000 lives.

Festivities were effectively scrapped in the occupied West Bank city of Bethlehem, revered as the birthplace of Jesus Christ, with few worshippers or tourists on the usually packed streets.

In the besieged Gaza Strip, the Hamas-run ministry of health said early Monday Israeli strikes had killed at least 18 people in the southern city of Khan Yunis, the centre of recent fighting.

Most residents have left Sderot, an Israeli town near Gaza, since war erupted with the Hamas attacks on October 7, but a reopened Jewish seminary hopes to bring life there back on course.

With the sound of outgoing artillery fire in the background, the study hall at the Sderot yeshiva -- less than five kilometres (three miles) from the besieged Gaza Strip -- is bustling with students.

"We want to be the guardians of the city, and we study the Torah here because that is the foundation of the Jewish nation," said rabbi David Fendel, director of the institution.

People donned Santa caps on beaches, ski slopes and streets around the globe on Monday to celebrate Christmas, as Pope Francis called for an end to the wars in Gaza and Ukraine that this year have cast a shadow over one of the world's favourite holidays.

Red and white Santa outfits appeared on surfers from Australia to Florida, on bicyclists in the smog-filled streets of New Delhi and intrepid souls braving chilly Channel waters for a holiday dip near Britain's Dover.

Pope Francis on Sunday kicked off global Christmas celebrations with a call for peace, as Israel's war on Hamas and Russia's invasion of Ukraine cast a shadow over one of the world's favourite holidays.

Children around the globe meanwhile tracked Santa, his reindeer and their present-laden sleigh with the help of www.noradsanta.org, a 3-D interactive website run annually by a joint US-Canadian military monitoring agency.