BEIJING — The death toll from a blast at a Foxconn factory in China, reportedly in a building where Apple's iPad 2 was being made, rose to three Sunday after a seriously injured worker died, state media said.

Two workers were initially killed and 16 injured in the explosion on Friday evening at the plant of a Foxconn subsidiary in Chengdu, capital of southwest China's Sichuan province, according to the official Xinhua news agency.

An initial investigation indicated that the explosion could have been caused by combustible dust in the polishing workshop, it said, adding that investigators had ruled out the possibility of sabotage.

Operations in the workshop and other plant sections with similar processes had been suspended for further investigation and safety checks, Xinhua quoted a spokesman for Hongfujin Precision Electronics (Chengdu) Co. Ltd. as saying.

Hongfujin is a subsidiary of Taiwanese tech giant Foxconn, the world's largest maker of computer components which produces items for Apple, Sony and Nokia.

The Economic Observer newspaper said the iPad 2 was being made in the building hit by the blast.

It is the latest incident to hit the embattled Foxconn, after at least 13 of its employees died in apparent suicides last year, which activists blamed on tough working conditions.

Foxconn employs about one million workers in China, about half of them based in its main facility in the southern city of Shenzhen.

Foxconn has been expanding its workforce in other parts of China as it seeks to scale back the size of its Shenzhen plant.

The firm opened the two-billion-dollar Chengdu plant in October last year, according to Xinhua.