German security officials are warning far-right groups not to conduct vigilante patrols along the country’s eastern border with Poland, amid a rise in the number of migrants crossing illegally in recent weeks.
Extremist groups including the far-right Third Way and Free Saxons have been using social media to recruit for their patrols.
“The state has the monopoly on the legitimate use of force,” said the head of the domestic intelligence agency in Saxony state, Dirk-Martin Christian.
Mr Christian said the move mirrored tactics used by right-wing extremists during the refugee influx in 2015 and 2016, and recent anti-lockdown protests.
German authorities have reported a sharp rise in the number of people illegally entering the country through Poland in recent weeks. On some days, officers have picked up several hundred people.
Many of those stopped are Iraqis and Syrians who have flown to Belarus and then crossed illegally into Poland, before making their way to Germany in the hope of applying for asylum.
Jens Schobranski, a spokesman for Germany’s federal police, said vigilante patrols were interfering with officers' work.
“Border surveillance is the job of the state and we are performing that task,” Mr Schobranski said.
“These stunts by people with right-wing attitudes are absolutely unacceptable and seem intended to undermine the state’s monopoly of the use of force.
“We’re taking decisive steps against it.”