Eleven Iranian pilgrims and their driver have died in Iraq after their minibus collided with a lorry and burst into flames, a health official said.
The bus carrying Shiite Muslims taking part in the Arbaeen pilgrimage hit a parked lorry on Sunday in Babil province, south of Baghdad, said local health authority spokesman Ahmed Al Jibouri.
“Eleven Iranians died on impact, along with their Iraqi driver,” he told AFP.
Iran shut its border crossings with Iraq on Friday over concerns for the safety of citizens leaving to take part in the pilgrimage.
Mr Jibouri said a fire had started and the driver of the lorry had been taken in for questioning. Four other pilgrims were in a critical condition, he added.
Iranian deputy interior minister Majid Mirahmadi said the bodies could not be identified “due to the seriousness of the accident and the fire”.
The Iranian victims' bodies “will be transferred to Iran for identification”, he told the country's Mehr news agency.
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 darkness at night.
But officials also say speed, using mobile phones and driving under the influence of drink or drugs contribute to crashes.
In July, the health ministry said 4,800 people, or 13 a day, died in traffic accidents last year in Iraq.
According to official statistics, almost two million Iranian pilgrims have entered Iraq to attend this year's Arbaeen — one of the world's biggest religious gatherings — in the Shiite shrine city of Karbala.
Arbaeen marks the end of the 40-day mourning period for the killing of Imam Hussein, a founding figure in Shiite Islam and grandson of the Prophet Mohammed, by the forces of the caliph Yazid in 680AD.