The frozen meat dumplings were produced at the Tianyang Food Plant in China's northern Hebei Province and, after the wave of poisonings, were found to contain the insecticide methamidophos.

One young girl who ate the dumplings was reportedly hospitalized in serious condition, China's state-run Xinhua news agency said.

Wang Daning, head of the Chinese group discussing the case, said China took the incident very seriously.

"We hope we can clarify facts related to the case as soon as possible and give the public a fair and reasonable explanation," he said.

Wang said tests on the other 2,000 packages of dumplings from the same batches sold in Japan showed no sign of contamination and all the other products made by the Chinese company were safe, Xinhua said.

After the closed-door talks, the Japanese officials were scheduled to visit the Tianyang Food Plant, officials said.