Police say Anthony Nephew, 46, shot wife and son and ex-partner and their son dead in Duluth on Thursday

A Minnesota man shot and killed his wife and son, and his ex-partner and their son, before killing himself, authorities said on Friday.

Duluth police have not determined a motive, but the police chief, Mike Ceynowa, said at a news conference that the shooter, named as 46-year-old Anthony Nephew, had a “pattern of mental health issues”.

In the US, the suicide prevention lifeline is 988 and the domestic violence hotline is 1-800-799-SAFE (7233). In the UK, Samaritans can be contacted on freephone 116 123 and the domestic abuse helpline is 0808 2000 247. In Australia, the crisis support service Lifeline is on 13 11 14 and the national family violence counselling service is on 1800 737 732. Other international helplines can be found via www.befrienders.org