US computing giant Microsoft said it was probing unrest at a supplier plant in China after about 150 workers protested last week, some reportedly threatening suicide. \"Microsoft takes working conditions in the factories that manufacture its products very seriously, and we are currently investigating this issue,\" Microsoft said in a statement, released to AFP on Thursday. The factory in central China\'s Wuhan city reportedly makes Xbox game consoles for Microsoft. It is owned by Taiwanese technology firm Foxconn, which has come under the spotlight after a string of suicides at its Chinese plants. Foxconn said Thursday the unrest had been \"successfully and peacefully resolved\". \"Early in the morning on January 4, approximately 150 employees at our Wuhan campus staged a workplace incident,\" Foxconn said in a statement to AFP. The firm said the incident was caused by a decision to transfer workers to another business unit within the complex, but gave no details of the protest itself. It added 45 workers involved in the incident had chosen to voluntarily resign, while others remained employees, making no mention of media reports that said some had threatened to commit suicide during the protest. In 2010, at least 13 Foxconn employees in China died in apparent suicides, which activists blamed on tough working conditions, prompting calls for better treatment of staff. In November last year, a woman employed by Foxconn jumped to her death from a company building in northern China over relationship problems, Chinese state media has reported. Foxconn employs some one million workers in China, where it owns plants that make components and assemble products for Apple -- including the iPhone -- plus Sony and Nokia.