The bomb exploded arriving at a main checkpoint at a northern entrance to the city, according to Reuters.
Over 50 cars were set no fire after the blast, with passengers trapped inside.
“Some of the victims were burned inside their cars,” a police officer said.
Of all the victims, at least six were security personnel and three civilians, according to two police officers at the scene, as cited by Al Jazeera.
Part of the checkpoint was destroyed.
Hilla is a largely Shiite Muslim city and is located 95 kilometers to the south of Baghdad.
Iraq has been torn by violent attacks since last April, with the numbers of dead jumping to its highest levels since the worst of the country’s sectarian bloodshed in 2006-2008.
8,868 people were killed in 2013, and over 1,400 people have died in January and February of 2014, according to UN statistics.