Police in several states across Germany have opened investigations into public displays of support for the Russian invasion of Ukraine, the RND newspaper group reported on Monday.

More than 140 investigations have been launched, most looking into the use of the "Z" symbol that has been seen in several protests in Germany alongside Russian flags.

The symbol has been associated with Russia's invasion after many of the vehicles that Russian forces drove into Ukraine had the letter painted on their side.

Several German states have classified the use of the symbol as unlawful support for the invasion.

"The public display of this symbol in connection with the Russian invasion will trigger an investigation when its use in the context means endorsement or support for Russia's war of aggression," a spokesperson for the Interior Ministry of the state of Magdeburg said.

'Symbol of solidarity'

In Germany's most populous state, North Rhine-Westphalia, the Interior Ministry has opened 37 cases.

"Of those, 22 investigations are looking into the use of the "Z" symbol as a sign of solidarity with Russian military commanders," a ministry spokesperson told RND.

In late March, a parade of cars drove from the city of Cologne to the city of Bonn, both in North Rhine-Westphalia, ending at a Soviet war memorial in a local graveyard.

The ministry spokesperson also said that there had been several incidents of property damage in connection with the war, and investigators were also looking into the use of the "Z" symbol in these cases.

The organizers of the Russian flag-waving protests have said that they are not endorsing the war, but are protesting against discrimination against Russian speakers in Germany.

Freedom of speech or criminal offense?

Investigators were also taking action in the states of Hamburg and Saxony-Anhalt, opening 17 and 19 cases into the condoning of criminal offenses respectively.

In the southern state of Bavaria, the Justice Ministry did not make public the number of cases, but the state's Justice Minister Georg Eisenreich said that Bavaria's public prosecutors were taking resolute action against people who endorse the illegal war.

Eisenreich defended the freedom of opinion as protected in the German constitution.

"Everyone in Germany may express their opinion. But freedom of expression ends where a criminal offense begins," he said, adding: "We won't accept the condoning of crimes against international law."

ab/fb (AFP, EPD)