BERLIN (Reuters) - President Joachim Gauck on Thursday condemned a recent rise in "vile" attacks on refugee shelters in Germany and warned that xenophobic attitudes were taking root in the country.

The comments by the head of state underline growing concern about hostility towards immigrants in Germany, which last year saw the emergence of the grassroots anti-Islam group PEGIDA.

Since the beginning of the year, there have been 150 attacks on refugee shelters -- nearly as many as in the whole of 2014.

"We are seeing xenophobic attitudes taking root and that some people aren't even shying away from carrying out attacks," Gauck said in a speech in Berlin.

"I'm referring to what we have recently experienced again with these vile attacks on refugee homes. It's unbearable."

Gauck called on citizens to stand up and defend Germany's democratic and liberal values by welcoming refugees from countries afflicted by war and human rights abuses.

Germany was shocked in 2011 by revelations that a small neo-Nazi cell, the National Socialist Underground (NSU), had murdered nine immigrants and a policewoman, and carried out bombings and bank robberies. Security services and police had failed for a decade to detect the NSU's existence.

Gauck, a former pastor in old Communist East Germany, has little real power as president but his words carry moral weight.

Chancellor Angela Merkel's government expects the number of people seeking asylum in Germany to more than double this year to a record 450,000.

The federal government has therefore agreed to double its financial support to federal states and cities, which are struggling with a surge of refugees, to 1 billion euros ($1.10 billion) this year.

But Berlin has also vowed to speed up repatriation of those whose asylum applications are rejected.

In the European Union as a whole, the number of arriving migrants -- mainly from Africa and the Middle East -- soared by 68 percent in the first five months of 2015 compared with the year-earlier period, the EU said on Wednesday.

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The EU's 28 member states are haggling over the details of a plan for sharing the burden of migrants reaching the bloc.

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(Reporting by Michael Nienaber; Editing by Mark Heinrich)