Consumers in China are panic-buying salt as they have become more concerned about food safety since Japan began releasing treated and diluted water from the Fukushima Daiichi nuclear power plant into the sea on Thursday.

The Chinese government has strongly opposed the move and suspended the import of all aquatic products from Japan in response.

Public anxiety in China about food safety has also grown, particularly of salt produced from sea water.

Salt shelves were emptied at a supermarket in the capital Beijing on Friday. Chinese media say supermarkets around the country are running out of salt.

The Chinese government has announced that it will strictly investigate suspected cases of speculative stocking of salt.

A salt producer said that sea salt only accounts for 10 percent of the salt people consume.

Beijing City officials are urging people against panic-buying, saying that the city keeps a sufficient stock of salt.

A man in his 60s said that he managed to buy two packets.

Another man in his 30s said that he strongly opposes the water discharge. He said that Japan claims the water is treated properly, but he suspects it must contain a lot of radioactive substances.

The Fukushima plant suffered a triple meltdown following the March 2011 earthquake and tsunami. Water used to cool molten fuel at the plant mixes with rain and groundwater. The accumulated water is treated to remove most radioactive substances, but still contains tritium.

Before releasing the water, the plant's operator is diluting the treated water to reduce tritium levels to about one-seventh of the World Health Organization's guidelines for drinking water quality.