Coca-Cola, Nestle, Unilever and Greece's giant dairy company, Delta, will withdraw their products from supermarket shelves in Greece during Christmas holidays in the wake of a contamination threat.
An anarchist group named Green Nemesis said in a statement posted online on Tuesday that it had "appropriated products from the main supermarket chains in the greater Athens area."
The group added that the products had been "poisoned with chlorine and hydrochloric acid."
The group said it would return the allegedly tainted products to supermarket shelves between December 22 and January 5, prompting authorities to issue alerts over the threat.
Police said relevant companies whose products had been affected would issue announcements on how they would yank their goods from shelves.
"Clearly there will be a withdrawal, the companies will be issuing the relevant announcements," a Greek police source said.
Reports added that Greece's anti-terror squad was looking into the case while the country's food safety watchdog was also informed about the threat.
Green Nemesis said tainted products belonged to the four major companies. It said they had laced salad sauce and tomato sauce as well as drinks, and milk, adding that they wanted the companies to pull out their goods from the store for a certain period during the Christmas.
"The operational aim is to sabotage the above companies, forcing them to fully withdraw their products for two weeks," the group said.
Green Nemesis sparked similar concerns in 2013 when it carried another contamination operation.