Russia infuriated the European Union on Thursday, by banning fresh vegetables from its 27 member states and faulting its health safety system for the death of 17 people from a lethal bacterial strain. The sanction was immediately denounced as \"disproportionate\" by a European Commission spokesman who said Brussels would demand an official explanation from Moscow. The Rospotrebnadzor watchdog said the ban was going into effect immediately and would remain in force until the European Union explained what caused the 17 mysterious deaths -- all but one of them in Germany. \"There is no evidence of infections going down, while the number of those sick with acute intestinal infection caused by enterohaemorrhagic E. coli (EHEC) has not been taken into sufficient account,\" the Russian statement said. Germany said on Wednesday that its initial assumption that the strain had come from organic Spanish cucumbers was wrong -- an admission that prompted the Spanish prime minister to demand financial compensation. State television said Russia imports about one-fifth of its vegetables from the European Union and most of the rest from China and Turkey. But the European Commission said the figure still amounted to more than three billion euros ($4.3 billion) in annual trade. \"It\'s disproportionate,\" the European Union\'s health spokesman Frederic Vincent told AFP, arguing that the ban unfairly punished countries where the vegetable crop was unaffected. \"The commission will write to Russian authorities to demand an explanation. This represents between three and four billion euros in European products exported each year,\" he said. The Russian consumer watchdog\'s chief Gennady Onishchenko -- a man known to throw himself in the centre of political and diplomatic disputes -- said the outbreak revealed faults in the common European food safety system. \"This shows that Europe\'s lauded health legislation -- one which Russia is being urged to adopt -- does not work,\" Onishchenko was quoted as saying by the Interfax news agency \"I am far from believing that my colleagues in Germany and other European countries lack professional skills,\" he said. \"But their hands are tied by an overly-politicised atmosphere.\" Onishchenko added \"it was obvious\" that Spanish cucumbers could not have been the true cause of the problem. Russia has been quick in the past to ban the import of products that are also produced locally. It has scuffled with the United States over chicken part shipments and banned wine and other imports from Georgia and Moldova during times of diplomatic tension with those two former Soviet republics. Critics of Russia\'s food policies say the bans serve the dual purpose of punishing the country\'s rivals while at the same time protecting domestic producers. Russia\'s western neighbour Belarus said it too was mulling an EU import ban. \"We are carefully following the situation,\" a source in the ex-Soviet republic\'s agriculture ministry told the Interfax news agency. \"We have not yet seen our Russia\'s colleagues\' official ban orders,\" the official said.