Four people from the same French family have died after falling from a seventh-floor balcony in Montreux, Swiss police have said.
Three adults and a child were declared dead at the scene, while a fifth family member -- a teenage boy -- was left seriously injured.
Swiss police have confirmed in a statement that the victims were all French citizens and members of the same family.
Officers had tried to execute a warrant in connection with the home-schooling of a child shortly before the incident, they added.
"The officers knocked on the door and heard a voice asking them who was there. After announcing themselves, the officers then heard no more noise in the apartment," the statement read.
"Unable to contact the potential occupants, they left the premises. In the meantime, a witness called the police to report that people had fallen from an apartment balcony."
The 40-year-old father, his 41-year-old wife, her twin sister and the couple's 8-year-old daughter died, while the 15-year-old son was hospitalised in serious condition.
Police say there was no other person in the apartment at the time. Authorities have opened an investigation “to determine the exact circumstances and reasons for this tragedy.”
A police spokesperson told The Associated Press that the five victims were found at around 07:00 CET on Thursday, outside a building near the lakeside city’s famed Casino Barriere.
Police and emergency teams erected white tents at the scene, and forensics investigators could be soon on the top balcony of the building.