Five people have been found dead after a shooting in a town in northern Switzerland, police say.

Residents heard shots in the town of Wuerenlingen shortly after 11pm local time on Saturday, police said.

Officers then found five bodies, including that of the suspected attacker, in a quiet residential neighbourhood.

Police said the attacker was 36-year-old but did not reveal his identity. He was a father of three but no longer living with his family.

He did not have a gun license and did not fire with a military weapon, the police spokesman said.

The suspected attacker 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 attacker, a 36-year-old who lived in Schwyz canton (state), south of Zurich. All were Swiss nationals.

Previously 'investigated'

The shooting appears to have been a "relationship crime", or the result of domestic dispute, Michael Leupold, Aargau canton (state) police chief, said.

Police "were able to rule out a terrorist background" or any other danger, he said.

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

The shooter had a record of violence and lived apart from his family in the nearby canton of Schwytz. In 2007, he was investigated for causing bodily harm and in 2012 he was probed after making verbal threats.

Police had searched his home on April 2 this year but no firearms were found.

Saturday's attack came after the man's wife and children left the family home and were housed in a shelter.

"The mother and her children are safe," said local police official Markus Gisin.

He said the investigation into the shooting was made difficult by the fact that there "are several crime scenes."

Wuerenlingen is a town of some 4,500 people northwest of Zurich, near the German border.

Source: Associated Press