Nine people have died in China after being injected with a drug containing a fake ingredient, authorities say.
They died after being given the drug, which treats gall bladder, liver and gastric disorders, at a hospital in southern Guangdong province.
The Chinese company that made the drug has blamed a supplier for delivering a toxic chemical in place of the genuine ingredients.
Several people linked to the firm have been arrested.
China's Premier Wen Jiabao has ordered an investigation into the incident, as well as a safety review of the country's pharmaceutical factories.
The patients fell ill at the hospital in Guangzhou city after being injected with fake Armillarisni A, medical sources said.
The drug had been made by Qiqihar No 2 Pharmaceutical Co Ltd, , based in north-eastern Heilongjiang province, Xinhua news agency reports.
Executives from the firm, including the general manager, a material buyer and a testing office director were being questioned by police, Xinhua said.
Dozens of people have been killed by fake and inferior products in China in recent years.
In 2004, at least 13 babies had died of malnutrition in the eastern province of Anhui after being fed fake baby milk.