At least two Christians were killed and 12 people wounded in a series of attacks on Christian homes in Baghdad, according to Iraq's interior ministry.
The worst attack was in the central Baghdad district of Al-Ghadir, where a homemade bomb exploded around 8pm (1700 GMT), killing the two Christians and wounding three others, including one Christian, an official from the ministry said.
Al-Ghadir is an area with a significant Christian population, though many have fled following the massacre and in light of threats by al-Qaeda to target them. The number of Christians left in Iraq is estimated at between 450,000 and 500,000, including around 300,000 Roman Catholics (down from 387,000 in 1980).
Between 800,000 and 1.2 million Christians lived in Iraq in 2003.
Iraq is still recovering from a massacre at a Baghdad cathedral in October. A group of Islamist extremists burst into the church of Our Lady of Salvation in Baghdad, murdering two priests, holding the congregation hostage and eventually killing more than 50 people.
The pope, in his annual Christmas message, urged political leaders to express solidarity with Christians in Iraq.