A police officer enters a house during a raid in Berlin, Germany, Wednesday, May 24, 2023. AP
The raids were ordered in an investigation targeting seven people aged 22 to 38 over suspicions of "forming or supporting a criminal organization", said a joint statement by Bavaria's police and prosecutors.
Fifteen properties were searched, two accounts were seized and an asset freeze was ordered.
The suspects are accused of "organizing a donations campaign to finance further criminal acts" for the group via its website.
At least 1.4 million euros ($1.5 million) had been collected in the campaign, said the authorities, adding that "these funds were according to current information mostly used for the committing of further criminal action of the association".
The authorities did not specify the "criminal action" it was referring to but said two of the suspects are alleged to have tried to sabotage an oil pipeline between Trieste, Italy, and Ingolstadt, Germany, deemed a "critical infrastructure" in Bavaria.
Dozens of climate activists from the group have found themselves before the courts in recent weeks over their traffic blockade actions.
The controversial tactics of Letzte Generation, from hunger strikes to throwing mashed potato on paintings in museums, have resulted in the group being described by some German politicians as "climate terrorists".
The activists argue however that their protests are vital in the face of inadequate action taken by the government and society in general to protect the environment and prevent catastrophic global warming.