Consumer prices, harmonised to make them comparable with inflation data from other European Union countries, rose by 2.1 percent year-on-year after an increase of 1.4 percent in the previous month, preliminary data from the Federal Statistics Office showed.

That compared with the consensus forecast for a 1.7 percent rise and was above the ECB's target of close to but just below 2 percent for the euro zone as a whole. Euro zone stocks and German bond yields rose after the data.

ING economist Carsten Brzeski said on Twitter: "Is #hyperinflation back? 2.1 percent in April! No, the Easter bunny is to blame."

He pointed to the cost of package holidays going up, with Easter falling later this year than last, and higher fuel prices.

"We will see a drop back clearly below 2 percent in May and then a lot obviously will depend on energy prices," he told Reuters.

With growth slowing and inflation expected to decline later in the year, the ECB already announced more support measures, such as a new round of ultra cheap bank loans, hoping this would boost growth by maintaining the flow of credit to the real economy.

But the German inflation rise and a stronger-than-expected euro zone growth figure suggest there is no reason for the ECB to offer more support, such as a tiered deposit rate, which would shield some banks from the side effects of negative rates, Brzeski said.

"There clearly is no case for further easing," he said.

ECB board member Benoit Coeure said last week that he saw no reason to create a tiered deposit rate that exempts banks from part of an ECB charge on their idle cash.

Inflation in the euro zone has long been below the ECB's target and ECB rate-setter Olli Rehn said on Friday that investors may be doubting the effectiveness of the ECB's monetary policy measures in boosting inflation.

Despite the ECB pursuing an accommodative monetary policy, inflation is not expected to hit the central bank's target for years to come.

A breakdown of non-harmonised national data showed the price of energy rose by 4.6 percent in April while the cost of services and goods also increased.

Economists expect annual euro zone inflation - due to be published on May 3 - to accelerate to 1.6 percent in April from 1.4 percent in March.

(Editing by Madeline Chambers and Alison Williams)

By Michelle Martin