The health department has said the suspected cases of food poisoning at Cheruvathur in the Kasaragod district were caused by Shigella infection.
District Medical Officer Dr AV Ramdas said the bacterial infection has been confirmed in four children who are under treatment.
It is understood that the health condition of all four is satisfactory. There are at least 57 persons admitted to various hospitals in Kannur and Kasaragod districts and Mangalore with similar symptoms.
The health department suspects Shigella to be the cause in the majority of the cases, though tests are required to ascertain the infection.
The food poisoning came to light after a teenage girl, Devananda, who consumed Shawarma from a cool bar in Cheruvathur died.
Others who had Shawarma from the same cool bar, named Ideal, are under observation.
Meanwhile, the health department said it is awaiting lab reports to know if the deceased was also infected.
Shigella infection (shigellosis) is an intestinal infection caused by a family of bacteria known as shigella. The main sign of shigella infection is diarrhea, which often is bloody.