Three Syrian refugee children were threatened with a knife by a group of young people in eastern Germany on Thursday. Police reported that the youth were chanting right-wing slogans after the incident.

A spokeswoman for the police could not confirm the nationality of the attacker, adding that their identity was not yet known.

The refugee boys aged five, eight and 11 were getting out of a bus in the eastern town of Sebnitz, around 40 km east of Dresden, when they were attacked, police said in a statement.

Racist crime has increased sharply since German took in just under 900,000 refugees last year. The problem is particularly pronounced in the states of former East Germany, where refugees have spoken of living in fear.

Police found several young people aged between 15 and 20 near the site of the attack but it is not yet clear if they were the attackers.

Germany, Europe’s largest economy, has taken in a total of 1.1 million migrants so far this year and last, upsetting some Germans who feel that their country is being overrun by foreigners with different cultures or religions to their own.

Support for the anti-immigrant Alternative for Germany (AFP) party has surged since last year’s migrant influx, particularly in eastern states where unemployment is generally higher than in the west.

In the capital, 50 more cases of far-right crime were reported against foreigners in the first six months of 2016 as in the same period in 2015, Tagesspiegel reports.