The accident happened in Babylon province around midnight as the group was returning in a minibus from the Shiite holy city of Karbala, a police source said.

Their vehicle collided with a 4x4 travelling in the opposite direction "due to high speed and the driver of the second vehicle's lack of attention", a statement from road traffic authorities said, adding two people were injured.

The police source said the vehicles caught fire.

Conflict, neglect and endemic corruption have left oil-rich Iraq's infrastructure, including roads and bridges, in disrepair.

Many roads are full of potholes and are plunged into total darkness at night.

"The number of traffic accidents doesn't stop rising. It's as if we were at war," said senior road traffic official Tarek Ismail late last month, quoted by state news agency INA.

He blamed a "lack of respect for speed limits", the use of mobile phones and driving under the influence of drugs and alcohol.

Last year, almost 1,000 people died in road accidents in Iraq, a country of around 41 million people, according to a traffic authority official.