Even before I can ask Interior Ministry spokesman Major-General Abdul Karim Khalaf a question, he greets me with a big smile. "All Iraqis are Christian today!" he says.

Many of the people attending the Christmas celebration appear to be Muslims, with women wearing head scarves. Suad Mahmoud, holding her 16-month-old daughter, Sara, tells me she is indeed Muslim, but she's very happy to be here. "My mother's birthday also is this month, so we celebrate all occasions," she says, "especially in this lovely month of Christmas and New Year."

Father Saad Sirop Hanna, a Chaldean Christian priest, is here too. He was kidnapped by militants in 2006 and held for 28 days. He knows firsthand how difficult the lot of Christians in Iraq is but, he tells me, "We are just attesting that things are changing in Baghdad, slowly, but we hope that this change actually is real. We will wait for the future to tell us the truth about this."