Authorities searched 15 properties across Germany in connection with a criminal investigation against a climate activist group that has gained notoriety for blocking major roads and disrupting airport traffic.

Seven members of the Letzte Generation, or Last Generation in English, are accused of forming or supporting a criminal organization and raising at least €1.4 million to allegedly finance further criminal acts, according to a statement released on Wednesday by Bavarian prosecutors. Two members are also suspected of attempting to sabotage an oil pipeline in April 2022.

The raids are tied to a string of criminal complaints that members of the public have filed against Letzte Generation since the middle of 2022, prosecutors said.

The group frequently engages in sit-ins on roads and highways to call for more stringent action to lower greenhouse gas emissions. Late last year, it disrupted takeoffs and landings at Munich and Berlin’s main airports after several Letzte Generation activists glued themselves to runways.