Tehran (CNN) -- A bus carrying Shiite pilgrims overturned in southwest Iran early Sunday, killing 19 passengers and injuring 23, according to Iranian media.
The incident caused two other vehicles to collide, killing five other people, the semi-offical Fars news agency reported, citing a local official.
The bus passengers were traveling from the holy city of Karbala, Iraq, to Iran's historic Shiraz, Fars reported. The fire chief in Shiraz , Ramin Talebi, blamed the accident on the driver falling asleep at the wheel.
CNN's Shirzad Bozorgmehr contributed to this report