Two specialist European agencies said Tuesday that a total of 150 salmonella cases had been detected in nine European countries, pointing the finger at a Kinder chocolate factory in Belgium, which was shut down after the salmonella outbreak was reported. 

"Most cases are children under 10 years of age, with many being hospitalized," the European Centre for Disease Prevention and Control and the European Food Safety Authority said in a joint statement.

According to the statement, as of April 8, nine countries had reported 119 confirmed and 31 probable cases.

The incidents happened in Belgium, France, Germany, Ireland, Luxembourg, the Netherlands, Norway, Spain, Sweden, and the United Kingdom.

Chocolate made at the Arlon factory in southeastern Belgium was found to contain salmonella, they added, urging countries to keep an eye out for new cases.

The factory's closure and the health concerns are a setback for its owner, Italian confectionery giant Ferrero, as they come at the height of the Easter holiday season knowing that its Kinder chocolates are popular supermarket purchases.

On Monday, Belgium launched an investigation.

Ferrero has issued a statement apologizing "sincerely" for the recent outbreak of salmonella cases.

The recall of the factory's entire production of the company's popular Kinder brand has been ordered by Belgium's food safety authority, AFSCA.

Ferrero, which also makes Nutella and Tic Tac candies, recalled certain varieties of Kinder chocolates made in Belgium in the United States on Thursday.

This followed recalls earlier this week in the United Kingdom and several European countries due to concerns about factory-made products.

Salmonella is a type of bacteria that causes diarrhea, fever, and stomach cramps in humans. It is one of the most common food-borne infections.

The majority of cases are caused by eating food tainted with animal or human feces.