Competitors test their skills in Shanghai

Wearing protective goggles and a mask, 17-year-old Zhang Jiahao from Shanghai took a deep breath and slowly started to guide his electric saw along the pen marks on the wood.

He was among the contestants in a joinery event at the 2017 China International Skills Competition, which opened in Shanghai and neighboring Suzhou, Jiangsu province, on Wednesday.

Seven participants in the joinery category, including four from overseas, must finish a piece of assigned work - a wooden casement with curves inside the frame like those on old churches or traditional Chinese architecture - by Thursday night, when the competition closes.