Police in Fukushima Prefecture, Japan, have searched the offices of a bus operator based in Gosen City, Niigata, in connection with a crash that left 21 people dead or injured on 6 August. The accident occurred on the Banetsu Expressway (a major highway running through Fukushima Prefecture in northeastern Japan) when a minibus carrying high school students from Niigata — travelling for a sports club trip — struck a guardrail. Investigators are working to establish the full circumstances under which the vehicle and driver were arranged for the journey.