It happened early this morning in Kirkuk, about 150 miles north of Baghdad.
The attack took place in Kirkuk’s Shatterlo neighborhood around 5:30 a.m., according to a police official who spoke to CNN on condition anonymity, because he’s not authorized to speak to the media.
The wounded included staff from the Holy Family Church and people with homes nearby.
Police said at least 20 people were injured in the attack, while the Interior Ministry put the number at 23.
The explosion damaged the church and a number of nearby houses, police said. Kirkuk is an ethnically divided mixed city located about 240 kilometers (150 miles) north of Baghdad.
In the past years, extremists have carried out major attack against churches.
An October 31 attack on the Sayidat al-Nejat Cathedral, or Our Lady of Salvation Church, left 70 people dead and 75 wounded, including 51 congregants and two priests.
Photo: AP/Emad Matti