A 33-storey apartment building is in flames in the South Korean city of Ulsan.

The fire is thought to have started on the 12th floor and has since spread to the upper storeys, according to reports from local media including the Yonhap news agency.

Windy conditions are believed to have helped spread the flames.

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Some outlets showed footage of the structure engulfed in flames and slabs of burning concrete falling to the street below.

There have been no reports of casualties so far.

A media report said rescue workers from the fire brigade had tried to evacuate the building as quickly as possible.

The building comprises 136 apartments.