Two trams have collided in a tunnel in Strasbourg, France, on Saturday.
At least 20 people have been injured, authorities said.
The crash occurred after one of the trams switched tracks and collided with a stationary tram at Strasbourg's central station, French broadcaster BFM TV reported.
Police and emergency services have asked people to avoid the area.
Strasbourg was the first major city in France to re-introduce trams in 1994. Since then, there had not been any major accidents.
More to come on this developing story.
zc/lo (AFP, Reuters)