The unknown suspects are thought to have formed a criminal organization, sources from the security forces told dpa on Friday.

According to Der Spiegel news magazine, a total of five arson attacks were carried out in the state of Thuringia in April and May. Their targets included a barracks used for concerts in the town of Ronneburg and a restaurant run by a known right-wing extremist in Kloster Vessra.

Meanwhile, a trial against four suspected left-wing extremists is due to begin at the Dresden Higher Regional Court on Wednesday. The suspects are accused of brutally beating right-wing extremists in Saxony and Thuringia.

A young woman from the city of Leipzig, who has been in custody since November 2020, is accused of being leading the militant group, which is said to be much larger. She is being tried alongside three men.

The president of Germany’s domestic intelligence service, Thomas Haldenwang, told Der Spiegel that a new level of violent attacks by left-wing extremists was evident in Germany.

“Several clandestine small groups have emerged that isolate themselves from the rest of the scene and specifically attack their political opponents,” he said.

The attackers have fewer inhibitions and are willing to countenance the death of a victim, he said.