BAGHDAD (AP) -- A suicide truck bomb targeted a police checkpoint in southern Baghdad on Wednesday night, killing 15 people and wounding 45, according to Iraqi officials.
The bomber detonated the vehicle, an oil tanker laden with explosives, security and hospital officials said, speaking on condition of anonymity under regulations. Three policemen were among the dead while the rest were civilians, and a number of policemen were also wounded, the officials said.
No one immediately claimed responsibility for the attack, but the Islamic State group has carried out similar attacks as their territorial hold in Iraq weakens.
Iraqi forces are fighting IS in western Mosul, where some 2,000 IS fighters are launching fierce counterattacks. After the beginning the operation to retake Mosul in October, Iraqi authorities in January declared they have liberated eastern Mosul, which is separated from the city's western neighborhoods by the Tigris River.
Western Mosul is densely populated and has proven to be a much more difficult fight for Iraqi and coalition forces, which have resorted to greater use of artillery and airstrikes to clear and hold territory.
A number of airstrikes in western Mosul have resulted in high civilians casualties, according to residents interviewed by The Associated Press. The U.S.-led coalition says a strike in western Mosul on March 17 likely resulted in civilian casualties and is investigating the incident.
Iraqi witnesses have said that airstrikes earlier this month killed scores of civilians. U.S. officials have said that the munitions used by the U.S.-led coalition that day should not have taken the entire building down, suggesting that militants may have deliberately gathered civilians there and planted other explosives that were detonated by airstrikes.
The militants have suffered a string of defeats over the past two years in the lead up to the Mosul operation, but have continued to regularly launch attacks in and around Baghdad. A series of large-scale bombings claimed by IS has struck Baghdad since the operation to retake Mosul began.
Iraqi and coalition officials have repeatedly warned that after Mosul, IS will likely return to its insurgent roots as it loses more territory in both Iraq and neighboring Syria.