Five people were killed over the weekend in a shooting at a house in the Swiss town of Wuerenlingen.
The mass shooting is believed to have taken place on Saturday, but police only discovered the bodies on Sunday morning.
The gunman is believed to be among the dead, in what police said was a family dispute. The killings are not terror-related.
Police found the bodies on Sunday morning lying down both inside and outside a building, the BBC reported. All those killed are reported to be adults.
Switzerland, although a country with low levels of crime, possesses one of the highest rates of gun ownership in the world.
The tiny European nation has a history of military neutrality but most men between the ages of 20 and 30 are conscripted in the militia, as the country's armed forces are known, and are required to keep their weapons at home in case they quickly need to fend off foreign aggression.
The motive for Saturday's killing is still unknown, but a police investigation is now underway.
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