Far-right demonstrators booed German Chancellor Angela Merkel as she arrived Wednesday at a refugee center hit by violent protests in a display of anti-migrant sentiment over the record influx of asylum seekers. About 200 people in the eastern town of Heidenau shouted "traitor, traitor" and "lying press," as she arrived at a shelter for asylum seekers that was the target of neo-Nazi riots.Merkel traveled to the site in Heidenau near Germany's eastern border with the Czech Republic to express support for refugees following the outburst of anti-foreigner violence over the weekend and a series of suspected arson attacks on asylum shelters. Merkel also planned to meet with refugees, aid workers and local officials on the site south of Dresden. Dozens of police were injured when a far-right mob threw bottles and fireworks at officers in an attempt to prevent asylum seekers from moving into the former hardware store over the weekend.The public show of hostility in Heidenau came as chaotic scenes erupted in the Hungarian border town of Roeszke with police firing tear gas at migrants. As Germany prepares to receive a record 800,000 asylum seekers this year, a spate of attacks has hit refugee centers, including two incidents reported just hours before Merkel's visit to Heidenau.President Joachim Gauck blasted a "dark Germany" behind the series of xenophobic attacks, as German leaders went on the offensive to quell the wave of anti-migrant violence. Gauck also praised the many "volunteers who want to show that there is a Germany in the light, a shining contrast to the dark Germany we witness when we hear about attacks on refugee centers or even xenophobic acts against people."Meanwhile, Germany's Social Democrats (SPD) were forced to evacuate their headquarters on Tuesday after receiving a bomb threat and flood of racist emails and phone calls the party said were linked to leader Sigmar Gabriel's visit to the eastern town of Heidenau. The centre-left SPD, which shares power with Merkel's conservatives, said that in the 24 hours after Gabriel's visit it had received 300 emails with "misanthropic" content and about 150 calls in which its employees were insulted and threatened. "We've got to assume that this is a political act," said SPD general secretary Yasmin Fahimi. The threats underscored how tense the situation in Germany has become as asylum seekers pour in from war-torn countries such as Syria, Iraq and Afghanistan, as well as Balkan nations in southeast Europe.Anti-immigration ideology and xenophobia have become more visible in the country as a result of the efforts of political parties like the NPD and Alternative for Germany (AFD), as well as anti-Islam and anti-immigrant initiatives like Patriotic Europeans Against the Islamization of the West (PEGIDA), which have staged anti-immigrant rallies and drawn thousands of people throughout Europe and especially in Germany. Attacks against refugees and asylum centers in Germany have increased sharply over the past year. Officials say there were some 202 such attacks in the first six months of 2015, as many as during the whole previous year.