Utah shooting: Teenager arrested after family - including three children - shot dead

One woman, two girls and one boy found dead in Grantsville home where teen opened fire

A quiet town near Salt Lake City, Utah has been rocked by tragedy after police arrested a teenage boy suspected of killing four members of a family, including three children, and injuring a fifth person inside at the same address.

The shooting is among the state's most deadly mass shootings and one of the first murder cases in Grantsville in nearly 20 years.

Police arrived at the home around 7pm on Friday and discovered the bodies of one woman and three children.

According to the Grantsville Police Department, the suspect was arrested at a nearby hospital after he was driven there by a person who visited the home after the shooting.

The boy, who police have described as a juvenile, faces 10 charges, including aggravated homicide. Police do not know how he was able to obtain a weapon and have not revealed identifying information because of his age.

The state's department of public safety and its crime laboratory are assisting local law enforcement with the investigation.

Officials confirmed that the victims lived together at the home, though police have not confirmed the identities or relationships of the victims, or their relationship to the shooter. A family member's fundraiser for the costs of medical and family care says a mother and her three children are among the victims. The fourth victim is reportedly the children's father and is in critical condition.

In a statement, the Grantsville Police Department wrote: "Our sincere condolences to the families and loved ones affected by this tragedy."

Utah Governor Gary Herbert said: "Our hearts are broken by the horrible news. We mourn over the loss of innocent lives."

He added: "Parents and grandparents, secure your firearms! Everyone, hug your loved ones tight. And remember love, not hate, will heal broken individuals and families."