State media report number of casualties currently unknown in blaze that engulfed building.

A major fire has broken out in a skyscraper in the central Chinese city of Changsha, state media have reported, adding that the number of casualties is currently unknown.

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“Thick smoke is spewing from the site, and several dozen floors are burning ferociously,” the state broadcaster CCTV reported.

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“Firefighters have begun work to extinguish the flames and conduct rescues at the scene,” it added.

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The blaze engulfed a tall building that housed an office of state-owned telecommunications company China Telecom, the report said.

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A photograph released by CCTV showed flames searing through the building in a built-up area of the city, as black smoke billowed into the sky.

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A video posted on social media by a local news outlet appeared to show the outside of the tower charred black.

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Changsha, the capital of Hunan province, has a population of about 10 million.

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