A rare tornado hit Sydney on Wednesday with destructive winds above 200 km an hour and cricket-ball-sized hail, bringing down trees and power lines, sheering off roofs and walls and causing flash flooding in Australia's largest city.

The Bureau of Meteorology issued the rare tornado warning around midday as the dangerous storm swept up the coast from Sydney's south, forcing some international and domestic flights to be diverted to other cities.

A witness described widespread damage at an industrial park in the hard-hit Kurnell neighborhood near the southern beachside suburb of Cronulla.