Berlin - Germany's emboldened far right has seized on a number of high-profile crimes allegedly committed by migrants to excoriate Chancellor Angela Merkel's liberal border policy.

Most recently, right-wing extremists have rallied over a knife attack last month in the eastern city of Chemnitz in which a German man was killed and an Iraqi asylum seeker is the prime suspect.

Police statistics indicate that crime in Germany has seen a steady decline in recent years. However, violent acts committed by foreign nationals have risen since the height of the refugee influx in 2015.

- Official figures -

Interior Minister Horst Seehofer, a vocal critic of Merkel's decision to let in more than one million asylum seekers over the last three years, issued a report in May showing that the number of crimes committed against persons or property in Germany fell to "the lowest level since 1992".

In 2017, police recorded 5,761,984 criminal acts, marking a 5.1-percent drop on the previous year.

- Link between migrant influx and criminality? -

In 2014, the year before the "migrant crisis", there were 6,082,064 crimes registered in Germany -- more than in 2017.

However, the ratio of foreigners among criminal suspects has climbed, from 28.7 percent in 2014 to 40.4 percent in 2016 before declining again in 2017 to 35 percent, the study presented by Seehofer in May showed.

Right-wing extremists rallied over a knife attack last month in the eastern city of Chemnitz

The following month, US President Donald Trump falsely asserted that immigration is driving up crime in Germany

"Big mistake made all over Europe in allowing millions of people in who have so strongly and violently changed their culture!" he tweeted.

A report completed by the BKA federal police force for daily Die Welt published at the weekend showed that crimes committed by foreigners (the large majority of them asylum seekers) fell last year by 2.7 percent on the previous year.

- The most violent crimes -

However, the most violent crimes including homicides show an increase among foreign offenders, according to the Welt report.

The number of German citizens killed by foreign assailants in the last three years rose steadily to 83 (out of a total of 731), from 62 and 52 the previous two years.

In one such lightning-rod case, a German court Monday jailed a failed asylum seeker claiming to be from Afghanistan for stabbing his 15-year-old ex-girlfriend to death.

Although there were doubts about his age -- he claimed he was also 15 at the time of the attack -- he was tried as a minor and sentenced to eight and a half years in jail.

Such crimes have been widely publicised on social media by the far right, which has held a series of rallies marked by xenophobic slogans and violence in Chemnitz in recent days.