The death toll from a killer bacteria outbreak rose to 36 on Monday, German health officials said, one day after warning that more fatalities cannot be ruled out. The Robert Koch Institute (RKI), Germany's national disease agency, said 3,228 people had fallen sick from the virulent EHEC (enterohaemorrhagic E. coli) or the linked kidney ailment haemolytic uraemic syndrome (HUS). On Sunday, German officials said 34 people had died in the country, but upped that figure to 35 on Monday. A woman who had travelled to Germany also previously died in Sweden. "For many days the number of new infections from EHEC or HUS communicated to the RKI has declined in the country," the agency said in a statement that confirmed the new toll. German Health Minister Daniel Bahr told Sunday's Bild am Sonntag newspaper that he was encouraged by the decline in new infections, but warned that more deaths were still possible. Germany's Federal Institute for Risk Assessment said Sunday the outbreak is the most serious of its kind recorded in the world to date. After several frantic weeks of searching, German authorities on Friday said they had identified the contamination source as being vegetable sprouts from an organic farm in Lower Saxony, northern Germany. The farm has been closed and all its products recalled. The farm cultivated sprouts from a variety of products including lettuce, azuki beans, mung beans, fenugreek, alfalfa and lentils. Authorities have said though that the farm in the northern village of Bienenbuettel had done nothing wrong. With German authorities only late last week dropping advice, particularly in northern Germany, to avoid uncooked tomatoes, cucumbers and lettuce, the scare has cost European farmers hundreds of millions of euros (dollars).