A US police officer has been shot and killed on her first day at work, the day after she was sworn in.

Ashley Guindon had been responding to a domestic dispute in Woodbridge, Virginia, about 32 km (20 miles) south of Washington, DC.

Two of her colleagues were also injured in the shooting and are in hospital, but no details have been released about their condition.

The suspect, a military serviceman, was unharmed and is now in police custody.

The suspect had murdered his wife then opened fire on officers as they approached, a police official told the AP news agency.

There was also a child in the house at the time of the incident, he said.

"It is with profound sadness that we announce that Prince William County Police Officer Ashley Guindon, one of the officers involved in this evening's shooting on Lashmere Ct, has died as a result of her injuries sustained during the incident" her department said in a statement on Saturday.

Prince William County Police had earlier tweeted a picture of Guindon following her inauguration on Friday, urging her and another new colleague to "be safe".