The spirit of Christmas turned up in the most unexpected of places this year, as shown by this Iraqi odontology student in a Santa Claus outfit who distributed gifts to impoverished children outside their shanty home in Iraq's Shi'ite holy city of Najaf on Sunday.

Farther north, several hundred Iraqi Christians flocked on Saturday to Bartella, which was recently retaken from Islamic State in Iraq and Syria (ISIS). They were celebrating Christmas for the first time since 2013, Reuters reported.

Once home to thousands of Assyrian Christians, the town emptied in August two years ago, when it fell to the ISIS blitz across large parts of Iraq and neighbouring Syria.

Iraqi forces took it back in the first few days of the United States-backed offensive that started in October, said Reuters.

In the first half of this year, 4.7 million children in Iraq - almost one in three kids - needed humanitarian assistance, according to the United Nations Children's Fund.

That number is expected to rise as military operations continue.