Four people have been detained after a missing radioactive source was retrieved in eastern Chinese city of Nanjing, local police said Sunday.
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The iridium-192 radioactive source went missing Wednesday when four workers with the Tianjin Hongdi Engineering Test Development Co. Ltd. were carrying out tests in a yard of a construction company under China's oil refiner Sinopec in Nanjing, police said.
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Hongdi reported the loss to police late Thursday night, prompting the city government to start an emergency response plan. The source was retrieved late Saturday afternoon.
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Police detained four workers with the Hongdi company on Saturday. They had violated working regulations and storage rules, which led to the missing of the source, police said.
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No casualties by exposure to the radioactive source have been reported. Â