TEHRAN -- At least 30 Afghans were killed and 83 injured when a truck overturned in southern Iran on Thursday, the official news agency IRNA reported Thursday.

Local medical official Mohammad Ali Ghanaat Pisheh told the news agency that the casualties were among a total of 125 Afghan illegal immigrants traveling in the 10-wheeler.

The cause of the early morning accident in the village of Khiareh in Fars province was still under investigation, he added.

Iran's roads are among the most dangerous in the world. At least 100,000 people have been killed in traffic accidents over the past five years in a country of some 70 million people.