NSW police caution teen trolley chuckers

Two youths have been cautioned by police after they hurled shopping trolleys from the roof of a Sydney shopping centre, injuring a woman sitting in her car.

The boys, aged 15 and 16, threw trolleys off the roof of Hurstville Shopping Centre in Sydney's south on Thursday night, smashing the windscreen of the car in which a woman and male driver were travelling.

The male driver had initially stopped when he heard a bang and crash, and saw a trolley plummet four storeys from the complex's roof onto a nearby bus, police said.

Minutes later, his own car was targeted as a trolley landed on his car.

The 50-year-old woman suffered minor injuries and was treated at the scene by paramedics.

Police released CCTV footage of the teenagers on Friday morning before the two boys turned themselves in to police.