At least 21 people were killed and about 20 were injured, including a Croatian national, after a bus carrying tourists veered off an overpass near Venice in northern Italy and caught fire, local authorities said on Tuesday.

The bus ran off the road and fell near a railway line in the district of Mestre, which is connected to Venice by a bridge. The cause of the accident has not yet been determined.

Authorities said the vehicle fell on power lines and caught fire around 7:45 p.m.

The bus was transporting tourists, including Ukrainians, French and Germans.

“The initial report shows that at least 21 are dead and more than 20 people are hospitalised, many of them in a very serious condition,” said Luca Zaia, the governor of the Veneto region, whose capital is Venice.

Among the victims are “Ukrainian tourists”, a spokesperson for the city administration told AFP, as well as Germans and French, ANSA reports. Among the injured are three Ukrainians, a Croat, a German and a Frenchman, the spokesman told AFP. The identification of the dead is underway.