A SWAT team descended on a quiet Utah neighbourhood after a man wearing a bomb vest allegedly told cops he shot his wife dead.

A 45-year-old unidentified man opened fire on authorities in Hyrum,   a little more than an hour from Salt Lake City – around 7.15am Sunday. 

Police then returned fire as the situation quickly turned into a stand-off.

Authorities also said neighborhoods were being evacuated.

The emergency response began when a man called police and said he had killed his wife.

Cache County Sheriff Chad Jensen said deputies arrived at the home around 5am.

The 45-year-old then allegedly opened fire on the officers, who took cover and urgently called in for a SWAT team.

The suspect is accused of then firing on the back-up when it arrived.

Negotiators arrived on the scene and were able to make contact with the man.

He later sent photos of himself wearing a bomb vest and explosives inside the house.

Authorities say no contact has been made for several hours.