Thousands of people demonstrated on Sunday against right-wing extremism in front of Berlin’s historic Brandenburg Gate, the city’s police department said. The police estimated the crowd at “several thousand,” according to a spokeswoman, while the climate protection group Fridays for Future, which had called along with others for the demonstration, put the number at 25,000. There were initially no incidents, the police said. Slogans saying the far-right Alternative for German (AfD) party is “not an alternative” could be read on banners and well-known climate activist Luisa Neubauer gave a speec…