BEIJING, Sept 26 — Three people have been found dead after a huge fire broke out at an unfinished research facility belonging to tech giant Huawei in the southern Chinese city of Dongguan, according to local authorities.

The government said it had launched an investigation after Friday's blaze at the building under construction in the Songshan Lake industrial development zone sent massive plumes of smoke into the sky.

The fire had started at a building where Huawei is developing a research base, the city government said, initially adding that all construction workers had been evacuated.

However in a statement later Friday, the government said a "thorough search by firefighters afterwards found three people dead inside the building.”

They were identified as employees of the industrial park management company, the government said.

The blaze was extinguished after 140 firefighters were called in to tackle the inferno, the local fire brigade said in a separate statement.

Footage broadcast by state media channel CCTV showed dark clouds of smoke billowing out of a blue and white building.

Pictures on social media overnight from the state broadcaster showed the blackened building surrounded by fire engines.

Huawei said the building was a "steel structure, and has not yet been put to use,” in a statement on the city administration's official social media account.

Huawei's main office campus is in the southern city of Shenzhen, but it has a large sprawling office complex in nearby Dongguan. — AFP