Nine patients in Germany had died of a form of kidney failure called hemolytic uremic syndrome (HUS), according to the World Health Organization (WHO), which cited May 31 figures as its most recent. Six had died of enterohemorrhagic E. coli, EHEC, a strain of E. coli that causes hemorrhaging in the intestines and can result in abdominal cramps and bloody diarrhea. One person in Sweden has also died.

Across Europe, 499 cases of HUS and 1,115 cases of EHEC have been reported, WHO officials said on its website.

In addition to Germany and Sweden, cases have been identified in Austria, Denmark, France, Netherlands, Norway, Spain, Switzerland and the United Kingdom.

All but two of the cases occurred in people who had recently visited northern Germany or, in one case, had contact with a visitor from northern Germany, the organization said.

Scientists at the Beijing Genomic Institute said the outbreak of infection in Germany is caused by a new "super-toxic" E. coli strain, though the US Centers for Disease Control and Prevention said the strain has been seen before.

Though WHO experts said it does not recommend any trade restrictions related to the outbreak, Russia on June 2 announced a ban on fresh vegetable imports from the European Union.

Russia imposed the vegetable ban because "no one wants to get sick. It is a natural protective measure taken in response to events that are happening in Europe today," Russian Foreign Ministry spokesman Alexander Lukashevich said.

In 2010, the imports of tomatoes and cucumbers from the EU amounted to, respectively, 11% and 5% of all imports of those vegetables into Russia, the Russian Agriculture Ministry said.