A suicide bomber driving a minibus packed with explosives has killed at least 45 people and wounded 157 in the southern Iraqi city of Hilla, police and medical sources say, according to The Guardian.

The attacker approached a main checkpoint at a northern entrance to the largely Shia Muslim city and detonated the minibus, a police officer said on condition of anonymity.

At least 50 cars were set ablaze with passengers trapped inside and part of the checkpoint complex was destroyed, the officer said. It was not immediately clear who was behind the attack, the suicide bombings being usually a trademark of al Qaeda-affiliated groups.

"I was sitting inside my kiosk when suddenly a horrible blast threw me outside and hurled my groceries up in the air. I saw cars set ablaze with people burning inside," said Abu Nawar, owner of a makeshift kiosk made of palm tree leaves near the checkpoint.

Police were using cutting equipment to break inside the burnt vehicles and lift out charred bodies, the police officer said, adding that the death toll was expected to rise.

"When a policeman suspected the minibus, he asked the driver to pull over for a check, but the vehicle exploded," the police officer said.

Bombings and other attacks killed almost 8,000 civilians in 2013, the worst period for the country since 2008.

The Islamic State of Iraq and the Levant, a militant group, has been behind many of the bombings. The Iraqi government is battling the Islamist group in the western province of Anbar, where the group holds territory in the cities of Falluja and Ramadi.