TEHRAN - At least 40 people were killed in a car accident in Tehran-Qom highway in northern Iran, semi-official ISNA news agency reported on Tuesday.

In the accident that took place late Monday night, two passenger buses moving in opposite direction collided and caught fire, Iran's Red Crescent Sosiety chief was quoted as saying.

Mahmoud Mozaffar said preliminary investigation showed that a tire of one of the buses, coming from Kashan to Tehran, blew up and the vehicle  crossed the rail guards, colliding with the bus travelling in the opposite direction from Tehran to Yazd.

"Unfortunately, in the accident over 40 people were killed and over 36 people were injured who were transferred to the hospital," said Mozaffar.

Official figures show that more than 20,000 people died and 200, 000 others were wounded in traffic accidents annually in Iran. Inexperienced drivers and low-efficiency of the cars and the roads are blamed for causing these accidents.