Apple Inc supplier Foxconn Technology Group said on Thursday it has reopened its electronics polishing facilities following a probe into an explosion in a China factory.

The Taiwanese company, Apple's main contract manufacturer for gadgets from the popular tablet to the iPhone, shut down polishing factories after three people were killed in a blast in a plant in Chengdu, the capital of China's Sichuan province, on May 20.

The investigation into the explosion at the Chengdu site, which is still closed, is ongoing, the company said.

Preliminary findings pointed to an explosion of combustible dust in a duct at a polishing workshop at the plant.

The plant explosion was the latest setback for Foxconn, whose flagship unit is Taiwan's Hon Hai Precision Industries group.

The company made headlines last year after reports emerged about poor working conditions at factories in southern China, which critics say may have helped drive several employees to suicide.

(Reporting by Poornima Gupta; editing by Andre Grenon)

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