Inflation in the euro zone snapped back to a record 3.6% in May amid soaring oil prices, according to a first estimate from the EU's Eurostat data agency.
The 12-month inflation rate had eased in April to 3.3% after hitting 3.6% in March, the highest level since the launch of the euro in 1999.
Recent record oil and food prices have pushed inflation higher, putting additional strain on consumers and businesses already struggling with slowing economic growth.
The bounce-back to 3.6% in May took euro zone inflation further away from the European Central Bank's comfort zone, which it defines as annual consumer price growth of close to but less than 2%.
The figures further complicate the ECB's task of keeping inflation under control in the face of an increasingly downbeat outlook for the euro zone economy.
The Frankfurt-based central bank has been on the lookout for any indications that record oil and food prices are feeding through into other prices and wages.
Recent record oil prices have sparked waves of protests across Europe led by striking fisherman and truckers increasingly pinched by the runaway cost of fuel.
The protests are ratcheting up pressure on governments to find ways of easing the pain and EU leaders are due to discuss the problem at a June 19-20 summit in Brussels.
