Five people have been found dead after a shooting in a town in northern Switzerland, including the suspected gunman, police said.

Residents heard shots in the town of Wuerenlingen shortly after 11pm last night. Officers then found five bodies in a quiet residential neighbourhood.

The shooting appears to have been a "relationship crime," or the result of domestic dispute, Aargau state police chief Michael Leupold said at a news conference. Police "were able to rule out a terrorist background" or any other danger, he added.

The suspected gunman first killed three people - a 58-year-old man, a 57-year-old woman and a 32-year-old man - in a house, criminal police official Markus Gisin said. He is then believed to have killed a 46-year-old neighbour outside the house before shooting himself.

The victims in the house were the parents-in-law and brother-in-law of the suspected gunman, a 36-year-old who lived in Schwyz state, south of Zurich. All were Swiss nationals.

The gunman's wife and three children were not targeted in the shooting.

Wuerenlingen is a town of 4,500 people north-west of Zurich.