Four people have been injured in a crash near Invercargill this morning.
Emergency services were called to the two-car crash on Palmerston St in Riverton about 8.30am.
They said crews were working to extricate one person from a vehicle at 9am.
The spokesperson said police and St John are on site with a rescue helicopter on its way.
A St John spokesperson said one person is in a critical condition, two are in a serious condition and one is in a moderate condition.
Three ambulances, a primary response vehicle and a helicopter from Dunedin were still on scene at 10.15am.
A police spokesperson said Palmerston St is expected to be closed for some time and traffic management will be in place.
"Motorists are asked to avoid the area if possible. The Serious Crash Unit has been advised," they said.