Five people, including two children, have been taken to hospital in Oslo, Norway, after an armed man commandeered an ambulance on Tuesday.

Police said they received reports of a man who left the scene of an accident with a firearm, which he aimed at people.

They say the man then hijacked an ambulance and sped away.

The ambulance was pursued by the police and followed before officers fired shots at the ambulance to stop it.

The stolen ambulance hit a baby carriage with two children inside, and three other people were nearly hit by the ambulance, police said.

When officers managed to stop the stolen ambulance, they found only the driver inside but later arrested a woman who was in the initial overturned vehicle and reported to be in the ambulance.

Police said they didn’t know why the man stole the ambulance.

"We do not yet have information that the incident is terror-related, but we are investigating widely and taking this very seriously," they said in a tweet.