The number of people who have died in Italy after being administered a flu vaccine made by Swiss pharmaceutical company Novartis, has risen to 13 according to reports.
The Italian Medical Agency (AIFA) has warned against panic and stressed there is not proof yet that it was the vaccine that led to the deaths.
Two batches of the product, called FLUAD have been banned as a precautionary measure.
AIFA said the European Medical Agency would start examining the problem on Monday, and would report back on Thursday.
The Italian authoritie had issued a partial ban on FLUAD on Thursday after being alerted that three people had died and a fourth had been taken seriously ill within 48 hours of being administered the drug.
More cases started to come to light in the following days.