Among the five were three teenagers as well as the driver and a chaperone, according to local media. Five others were critically injured.

　　Forty two passengers, mainly young Russian tourists, were on the Polish-registered bus, when it drove off the E34 highway around 6:30 a.m. (0430 GMT) near the city of Antwerp, media reports quoted Belgian officials as saying.

　　The bus was traveling from Russia's Volgograd region to Paris.

　　The cause of the accident was still unclear. There has been media speculation that the driver may have fallen asleep.