SA man charged over Murray Bridge siege

A South Australian man has been charged with arson and assaulting emergency workers after an incident in which an air conditioning unit was thrown at a police officer.

The 33-year-old was detained at a Murray Bridge address, east of Adelaide, on Friday after police fired three shots at the man who they allege was armed, had threatened officers and had set fire to the front of the property.

He suffered minor injuries in the incident and has been refused bail to appear in court on Tuesday.

When patrols first arrived the man barricaded himself in a room after allowing five other people, including two children, to flee the house.

"During the incident, the man threw an air conditioning unit at a patrol officer but thankfully, he was not injured," police said in a statement.

At that stage, elite STAR Group officers and negotiators were called to the scene to assist.

"As one of a range of tactical options available, STAR Group officers discharged three less than lethal rounds at the suspect," police said.

"After several hours of negotiation, the man was taken into police custody without further incident."