Pope Francis pays tribute to Christians persecuted by Isis

Pontiff says there are more Christian martyrs now than in Church's early days

Iraqi Christians light candles inside a shrine in the grounds of Mazar Mar Eillia Catholic Church, which has now become home to hundreds of Iraqi Christians who were forced to flee their homes as Isis advanced towards them, 12 December, 2014 in Erbil, Iraq.

Pope Francis has paid tribute to Christians in the Middle East who have been persecuted by Islamist militants.

The pope praised those who had clung to their faith and said there are more Christian martyrs now than in the Church's early days.

He spoke to thousands of people in St Peter's Square for his holiday blessing on the feast of St Stephen, the first Christian martyr.

The Pontiff mentioned the persecution of Christians in Iraq, many of whom were able to spend their first Christmas since 2013 in churches, after towns and cities were retaken from Isis.

"This was an example of fidelity to the Gospel," he said. "Despite trials and dangers, they courageously show that they belong to Christ," he said.

"Today, we want to think of them and be close to them with our affection, our prayers and even our tears," the pope added.

Christians in northern regions of Iraq held by Isis were given an ultimatum: pay a tax, convert to Islam, or die by the sword. Most of them fled to the autonomous Kurdish region to the east.

Leaders of various churches, including the Coptic Church in Egypt, whose members have been beheaded and churches bombed, have called the fact that Christians of all denominations were being killed in the Middle East an "ecumenism [unity] of blood."

"There are more Christian martyrs today than in the first centuries," the pope said.

He has often denounced Isis and condemned the concept of killing in God's name.

Additional reporting by Reuters