Police probing a lethal blaze that destroyed a China Central Television (CCTV) tower during a firework display have arrested 12 people, including the former head of the company's construction office.

All were held on suspicion of "causing an accident with dangerous articles" in a move sanctioned by the Beijing Municipal People's Procuratorate.

As well as the ex-chief of construction, Xu Wei, those formally arrested included three employees of the construction team and eight workers from Hunan Sanxiang Fireworks Company. The company, based in Hunan province, supplied the fireworks, reported Xinhua News Agency.

One of the three CCTV staff is Sha Peng, chairman of Supernova Media Development Company, an intermediate firm between CCTV and Sanxiang, added Xinhua.

All 12 suspects had been held in detention since February 11. Investigators were also awaiting the green light to officially arrest another five suspects, the Beijing News reported.

If convicted, the maximum punishment for the charge is seven years in prison.

One firefighter was killed and seven others injured, including six firemen and a construction worker, in the blaze. It tore through a 30-storey building in the State broadcaster's complex in the Beijing Central Business District on February 9, the date of this year's Lantern Festival.

"It is too early to tell who should be made responsible for the blaze," an official of the Beijing Municipal People's Procuratorate, surnamed Zhao, told China Daily yesterday. "The case is still under investigation, and a court trial has not been set."

CCTV is alleged to have hired a company to ignite several hundred "grade A" fireworks outside the building, which housed the almost completed Mandarin Oriental Hotel, for the festival and to mark the end of Lunar New Year celebrations. Fireworks were allowed in downtown Beijing until midnight during Spring Festival but powerful grade A fireworks must have police approval before being set off.

According to the Beijing Fire Control Bureau, CCTV failed to get a permit. It even ignored warnings from police officers for it to cancel the fireworks show, the bureau said.