BAGHDAD/TIKRIT, Iraq, Jan 2 -- At least 16 people were killed by a car bomb in a busy square in Baghdad's sprawling Sadr City district on Monday, while Islamic State attacks on military positions north of the capital killed 16 pro-government fighters, sources said.
There was no immediate claim of responsibility for the blast, which also wounded more than 40 people, but Islamic State regularly targets civilian areas in the heavily fortified capital, even after losing most of the northern and western territory it seized in 2014.
Three bombs killed 29 people across the capital on Saturday, and an attack near the southern city of Najaf on Sunday left seven policemen dead.
U.S.-backed Iraqi forces are currently fighting to push Islamic State, the Sunni Muslim militant group, from the northern city of Mosul, the fighters' last major stronghold in the country, but are facing fierce resistance.
The recapture of Mosul would probably spell the end for Islamic State's self-styled caliphate, but the militants would still be capable of fighting a guerrilla-style insurgency in Iraq, and plotting or inspiring attacks on the West.
Since the offensive began on Oct. 17, elite forces have retaken a quarter of Mosul in the biggest ground operation in Iraq since the 2003 U.S.-led invasion that toppled Saddam Hussein. Prime Minister Haider al-Abadi has said the group would be driven out of the country by April.
As clashes continued in and around Mosul on Monday, Islamic State also targeted military positions away from the main battlefield.
Militants attacked an army barracks near Baiji, 180 km (112 miles) north of Baghdad, killing four soldiers and wounding 12 people, including Sunni tribal fighters, army and police sources said.
They seized weapons there and launched mortars at nearby Shirqat, forcing security forces to impose a curfew and close schools and offices in the town, according to local officials and security sources.
Shirqat mayor Ali Dodah said Islamic State seized three checkpoints on the main road linking Baiji to Shirqat following the attacks. Shelling in Shirqat had killed at least two children, he told Reuters by phone.
In a separate incident, gunmen broke into a village near Udhaim, 90 km (56 miles) north of Baghdad, where they executed nine Sunni tribal fighters with shots to the head, police and medical sources said.
At least three pro-government Shi'ite militia fighters were also killed and seven wounded when militants attacked their position near Udhaim with mortar rounds and machine guns, police sources said.