Investigators suspect the victims consumed vinegar that was put in two plastic barrels that had previously been used to store toxic antifreeze, the official Xinhua news agency reported.

It said the mass food poisoning occurred on Saturday night in a village close to Hotan city in Xinjiang. The victims were Muslims who were sharing an evening meal after the daily fast observed during Ramadan.

Xinhua said children as young as six were among the dead. One person was in a critical condition.

Authorities were still testing to confirm the source of the poisoning, it said.

China's food safety record has been battered by the rampant use of illegal or substandard additives by unscrupulous food producers. Milk powder laced with the industrial chemical melamine killed at least six children and made 300,000 ill in 2008. Producers added the nitrogen-rich melamine powder so their milk would seem higher in protein.

Revenge attacks using rat poison or other chemicals are also common in China, where access to firearms and other deadly weapons is tightly controlled. In April, three children died and 35 others became ill after drinking milk tainted with nitrite. An investigation showed that a local dairy farmer had put the poison into a competitor's milk supply.

Accidental contamination is also a problem, caused by poor hygiene, particularly in rural areas, and weak quality control by regulators.