German police said on Tuesday that they started an investigation after bottles of drinks containing deadly poison were found in two supermarkets in Munich.
The poison was found at the two locations in four separate incidents, and in three of the four customers consumed small amounts of the toxic liquid, police said.
Two women between the ages of 34 and 42 had to receive immediate medical attention after drinking.
The third, 48, suffered from symptoms such as dizziness and nausea, but did not require medical attention.
The fourth bottle found to contain poison had not yet been sold, they said.
The police have not yet determined the motive for the crimes, and a police spokesman said the blackmail is unlikely because the supermarkets have not received any demand so far.
They advised the public to be aware of any unusual odors from drinks and to inform them immediately if the substance was suspected in any way.
(dpa / NAN)