Three people have been injured after a landslide in western Sweden caused a sinkhole to open on a major highway.

Police said at least four cars and a bus skidded off the road and crashed, leading three people to be admitted to hospital.

Photos and video showed a sinkhole 500 metres (1,640 feet) wide that had opened up on the E6 highway, which runs from southern Sweden to Norway, not far from Sweden’s second largest city of Gothenburg.

Sweden Landslide Highway Collapse
Cars, buses and lorries skidded off the road to avoid the sinkhole (Adam Ihse/TT News Agency via AP)

Several buildings and facilities were also damaged.

Police spokesman August Brandt told Swedish public broadcaster SVT that Swedish emergency services received alarm at 1:45 am that a substantial part of the E6 had collapsed in Stenungsund.

Emergency officials were searching with specially trained dogs and staff to ensure there were no people trapped in the debris.

The cause for the landslide was not immediately known.

Sweden Landslide Highway Collapse
Emergency services are searching to ensure that there are no people trapped in the debris (Björn Larsson Rosvall/TT News Agency via AP)

Swedish media said the area has seen substantial construction activities involving blasting and excavation work recently and a large amount of rain has fallen in the past few days.

Swedish police have begun a preliminary investigation.