Police inquiries are ongoing after a 59-year-old man was injured by a falling trolley allegedly tossed from an upper level of a shopping centre by a teen girl.

Emergency services were called to the centre on Victoria Ave in Chatswood, Sydney just before 12pm on Monday.

The man had been walking on the ground floor when he was struck by a trolley allegedly thrown from a level above.

He was treated for head and facial injuries by paramedics before being taken to Royal North Shore Hospital in a stable condition.

A 13-year-old girl was arrested at the scene and taken to Chatswood Police Station.

The shopping trolley was seized for forensic testing.

NSW Police told 7NEWS.com.au that inquires are ongoing.

Anyone with information should contact Crime Stoppers.

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