A police officer is fighting for life and another is seriously injured after they were stabbed and their attacker shot dead in a small South Australian town.
Sergeants Ian Todd (53) and Jordan Allely (32) were stabbed when they went to a house in Crystal Brook on Wednesday morning.
They had gone to the Symons St property to follow up on a fairly minor incident at the local supermarket the previous day.
Police Commissioner Grant Stevens said Sgt Todd's injuries were life-threatening and he had been airlifted to Royal Adelaide Hospital in a critical condition with stab wounds to his neck, arms and hands.
Sgt Allely was in a serious but stable condition with wounds to his right leg and arm. He was also airlifted to RAH.
Sgt Allely is officer in charge at Crystal Brook, about 200km north of Adelaide, and Sgt Todd holds the same role at nearby Port Germain. Both have relatives in the force.
Mr Stevens did not identify the offender but said he was found dead by police who responded to the first calls for assistance.
He described both officers as highly regarded in their local communities.
"They're good people. They are respected. The way they do their job is also respected," he said.
"I'm sure this will be felt quite harshly by those local communities.
"This is not an indication of the type of activity we normally see in small regional communities but we really don't know what's happening beneath the surface in some situations."
A commissioner's inquiry is under way along with a coronial investigation with major crime detectives, a forensic science team and internal investigations officers expected to remain at the scene for some time.
Both officers were wearing stab-resistant vests and had body-worn cameras.
Mr Stevens said their families were being taken to Adelaide and the force was giving them as much support as possible.
"This is something we accept as a possibility as a result of the nature of the work we do," he said.
"There are inherent dangers in policing but our officers are trained to conduct their duties as safely as possible.
"The sad reality is that police officers are injured quite frequently on duty and we're very hopeful both ... Ian and Jordan come through the injuries they've received."
A shop worker in Crystal Brook, who believed she served the dead man earlier in the day, said they had chatted about the rain and his dog.
"Not long after we found out there was a siege down the street where he lived," she told Adelaide radio FIVEaa.
"From there we found out more information, exactly what did take place.
"Which is pretty scary and hard to hear. These things don't really happen to a small country town very often."
SA Police Association President Mark Carroll said the incident showed how quickly situations could escalate.
"Policing is a highly dangerous occupation. We try to be as safe as we possibly can," he said.
"But it's so unpredictable. People can do things in an instant."
SA Premier Peter Malinauskas said the incident "will be difficult news for the South Australian community to absorb".
"Our frontline workers do an inherently difficult and dangerous job each day when they go to work," he said.
"They exercise this duty with courage and bravery."
No South Australian police officer has been killed while on duty for more than 20 years.