A gunman has shot and killed three people in a NSW country town before going on the run, sparking a lockdown and major police operation.

The horror unfolded in Lake Cargelligo, a community of 1200 residents in the NSW central-west, on Thursday afternoon.

The shooter fired bullets at a woman and man who were in a car on Bokhara Street at about 4.20pm.

A short time later, another woman was shot dead in a driveway at Walker Street. The man she was with was also shot and rushed to hospital in a critical condition.

In total, two women and a man were killed in the space of about half an hour.

NSW Police released the identity of the alleged shooter on Friday morning in a public appeal for help to locate him.

Julian Ingram, also known as Pierpoint, aged 37, is wanted on an outstanding warrant for murder.

He is described as of Aboriginal/Torres Strait Islander appearance, about 165cm-170 centimetres tall, medium build with short dark hair and brown eyes.

He was last seen driving a council vehicle — a Ford Ranger utility with NSW registration DM-07-GZ, a metal tray back, high visibility markings on the side and an emergency light bar on the roof.

Anyone who sees Ingram is urged not to approach him and to contact triple zero immediately.

Julian Ingram is on the run and wanted. Photo: NSW Police

Media reports say the shooter and victims knew each other.

Sunrise reports that the first woman victim was the ex-partner of the shooter. She was reportedly with her new boyfriend, who was also killed.

“At this stage police have identified an offender, who is still at large,” Assistant Commissioner Andrew Holland said.

“There are concerns that this offender may be armed with a firearm … the offender is currently on the move, and we are looking to try to locate this offender.

“We have a large search in the area currently under way.”

Police ordered a lockdown of the town and told residents to stay indoors. Roads were also closed and motorists were advised to avoid Lake Cargelligo.

“Due to a police operation, motorists are unable to travel into Lake Cargelligo and the surrounding area,” police said.

“Delay your trip. Avoid the area and use an alternative route. Emergency services remain on site.”

Extra officers have been brought in from surrounding areas to help with the search. They include tactical operations police, search co-ordinators and air crews.

“The scene faced by the emergency services officers at that time would have been horrendous,” Holland said.

“What I will say is that it’s a tragedy that has taken place in a very small town that will have a big effect on the community,” he said.

“Any death in a small country town is confronting, but again, a scene where you have people shot by firearms is obviously going to make people very, very tense and very, very concerned.

“We have a large search in the area under way and are requesting people remain indoors… for their own safety.”

A staff member at the Commercial Hotel in the centre of town, who did not wish to be named, said there had been a lot of police activity after what they believed was a shooting in a house.

“I’m just inside, trying to not be around,” they said.

A manager of a local motel said it was “a little bit scary” in Lake Cargelligo and she believed more police were headed to the area.

Roy Butler, the independent member for Barwon, described the situation as “tragic news”.

“It’s a terrible situation, and it’s still live, so we don’t have much information. My thoughts are with the victims and their families,” he said.

“As there has been a number of shootings and the offender has not been detained – please stay indoors until the advice changes.”

Anyone with information in relation to the gunman’s whereabouts is urged to contact Crime Stoppers on 1800 333 000.

NSW Police have also appealed for anyone in the Lake Cargelligo area who may have mobile phone or dashcam vision, CCTV, photos, screenshots, or other material relevant to this incident. It can be uploaded at a bespoke link here.

-with AAP