German police launched a manhunt Friday for a suspect who claimed responsibility for a string of sabotage attacks targeting the country’s power grid this week, after authorities discovered suspected explosives at his home, officials said.

In the letters, sent to authorities and media, the 48-year-old man ​stated his opposition to fossil fuels as a motive for the attacks, the ​interior ⁠minister for the western state of North Rhine-Westphalia, Herbert Reul, said on Friday evening.

Federal Interior Minister Alexander Dobrindt, addressing the same press conference, said the evidence pointed to a case of "climate extremism".

Germany has been the focus of European fears about the vulnerability of critical infrastructure this week, ahead of a closely watched state election on Sunday where the far-right, Russia-friendly Alternative for Germany (AfD) leads the polls.

It also formally blamed Russia this week for a drone attack in August at Leipzig/Halle airport as part of hybrid warfare meant to intimidate and divide countries that have supported Ukraine since Russia's full-scale invasion in 2022. Russia has dismissed the allegations as baseless.