An explosion occurred in an industrial area of Vallingby in western Stockholm in the early hours of Wednesday morning, causing damage to nearby cars and buildings including an apartment hotel, according to local media. Police spokesman said several people suffered minor injuries and some of them were hospitalized, adding that one of the victims had been injured by glass shards following the explosion. The cause of the explosion is so far unknown, authorities say. The area has been cordoned off and an investigation has been launched, local media report. A witness who was sleeping in the hotel as the explosion happened told local media that windows were broken everywhere in the building.