An indoor stadium under construction in east China's Shandong Province caught fire at around 11:30 am today and the site is still ablaze at press time.

Witnesses said the f ire started on the roof of the stadium, which is part of the Olympic Sports Center in the eastern suburbs of Jinan, a sporting complex that is being built for next year's National Games.

No casualties have been reported so far.

Xinhua reporters at the site saw flames blazing nearly two meters tall. At least seven fire engines have arrived, carrying dozens of firemen who are still trying to extinguish the blaze.

This is already the second fire at the site in four months. The same stadium caught fire on July 27 and lasted for four hours. No death or injury was caused but the flames spread to about 3,000 square meters of the structure.

Investigators said sparks sprinkled out during the welding process were blamed for the previous accident.

Jinan will host the 11th National Games, China's biggest sporting event, next year. The four-yearly event was held last time in Nanjing, eastern Jiangsu Province, in 2005.