According to police, the victims were all French citizens or members of the same household. Police said that officers had attempted to execute a warrant for the home-schooling and arrest of a child just before the incident.

Police released a statement naming the victims as a 40 year-old man, his 41 year-old wife, their twin sister, and the couple’s 8 years-old daughter. The couple’s 15-year old son sustained serious injuries.

Police said that authorities have launched an investigation to determine the circumstances and causes of this tragedy. Police said that it is possible to exclude the presence of another person in an apartment during the facts investigation.

Alexandre Bisenz (regional police spokesperson) told The Associated Press that he could not immediately confirm reports by Swiss media that the five had jumped off a building.

Bisenz said to the AP that they were found outside a building close to the city’s famous Casino Barriere at 7 a.m.

Police stated that two officers knocked at the apartment’s door and asked for identification.

Police stated that they were unable to contact the potential occupants and so they fled the scene. “In the interim, a witness called police to report that two people fell from an apartment’s balcony.”

Montreux is a picturesque lakeside city that is well-known for its annual jazz festival and as a tourist hotspot.

On the spot, police and emergency personnel set up white tents. Forensics investigators were seen on the roof balcony.