A motorist has been tasered during a carjacking in Sydney's south-west.
The 37-year-old man was travelling eastbound along the Hume Highway at Yagoona last night when a car rammed his Toyota Camry station wagon from behind.
The man stopped his car - three men got out of the vehicle behind and approached his car.
One then tasered him - the men pulled him out of his car and drove away in it.
Police say his vehicle was found 20 minutes later at Sefton - on fire and dumped in a canal.
Quick thinking officers searched the area and located three men parked in a car nearby - they've been arrested and are currently being questioned.
Three 21-year-old men are due to face Bankstown local court.