In its annual report, Germany's domestic intelligence service (BfV) showed a 42 percent increase in violent acts by extremists associated with the far-right in 2015, describing attacks against journalists, politicians and refugees.

The report shows a recorded 1,408 violent crimes, compared to 990 such crimes in 2014.

During the same period, seventy-five arson attacks against refugee centers were recorded, up from just five a year earlier.

The report revealed the first full year data to be released since Germany saw the arrival of around 1.2 million migrants, which has led to a growing anti-foreigner sentiment.

It said the violent acts against immigrants did not generally appear to be systematically orchestrated, though many of the arson attacks did bear signs of careful planning and preparation.

Germany is home to an estimated 11,800 violent far-right extremists, the report added.

Fears of right-wing terror

"Current investigations against the suspected development of terrorist groups point to the possible emergence of right-wing terrorist structures in Germany and the need for the government to take rigorous action," the interior ministry said in a statement along with the report.

Support for extreme left and right groups is growing

Intelligence officials also highlighted the role of social networks in "agitation and radicalization," adding that uninhibited hate speech dehumanises minorities and fuels real-world violent crime.

At the same time, acts of violence by members of far-left groups also rose sharply, to 1608 offences from 995 the previous year. The report said those attacks often targeted far-right activists or police.

The intelligence service also pointed to the rising threat posed by Islamists, estimating their number at about 10,000. The report said it assumed that some jihadists and war criminals had entered the country with the massive refugee influx.

Other potential threats were posed by "self-radicalised" individuals, jihadist fighters traveling to and from Syria and Iraq, and possible sleeper cells from militant groups, it said.

Watch video 03:38 Share Jaafar meets 'PEGIDA' Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/1Gqw7 PEGIDA demonstration in Dresden turns violent

mm/jr (AFP, AP, Reuters)