Two men have been charged after dramatic scenes in Sydney and raids in the city's south-west after a police sting targeting extortion.

At least six heavily armed officers in riot gear emerged from two Nissan Patrols on King Street, Newtown, just after 3pm on Friday.

Police gather on King Street after pulling over a car to arrest a man. Credit:Kristopher Perry

They stopped a Toyota Yaris and ordered the male driver and his female passenger out of the car.

The driver, a 21-year-old man, was arrested in front of shocked onlookers. The woman was escorted from the scene.