(CNN)Five people died in the northern Swiss town of Wuerenlingen after residents heard shots fired late Saturday, federal police said.
5 dead after shooting in Swiss town
Responding officers from Aargau County Police found their bodies lying outdoors and inside a residence.
A large group of officers and investigators worked through the night on the investigation, which is ongoing, Aargau police said in a statement. The state prosecutor's office has opened a criminal inquiry.
Authorities have not established a motive or identified the victims.