HANGZHOU - Three firemen died while trying to extinguish a factory blaze which broke out in the early hours of Tuesday in East China's Zhejiang province, fire authorities said.

The blaze broke out at around 3 am in the workshops of Hangzhou Yusei Machinery Co Ltd in Xiaoshan district of Hangzhou, the provincial capital of Zhejiang.

A firefighter is seen on the accident site in Guali township of Xiaoshan district in Hangzhou, capital of East China's Zhejiang province, Jan 1, 2013. [Photo/Xinhua]

Up to 50 fire engines attended the scene and put the blaze under control by Tuesday noon.

The three firefighters, all men, went missing when they were trying to put out the flames. They were later found by rescuers and rushed to a hospital, but died despite doctors' efforts.

The burning materials such as plastic products, cartons and foam resulted in a huge amount of toxic smoke, according to the provincial fire fighting authorities.

The cause of the fire is under investigation.