BERLIN (Reuters) - Six Berlin nightclubs opened their doors this weekend to some 2,000 revellers free of masks and social distancing restrictions in a pilot project to assess whether testing for COVID-19 could prevent another lockdown for the city's night life venues.

       To be admitted to the clubs, all participants in the project, named "Clubculture Reboot", had to have tested negative on Friday with a Polymerase Chain Reaction (PCR) test, the most reliable commonly-used method of detecting COVID-19.

       They will be offered a cash incentive to get follow-up tests this coming Friday.

       Some 20 clubs applied to take part in the project, initiated by the Berlin Culture Ministry and scientists from the city's Charité hospital. The six selected clubs were chosen based on their ventilation systems, city districts, and music genre.

       The idea of the study is to determine how to safely reopen nightclubs without anyone getting infected. If the pilot is successful, further such events could take place in the future.

       While COVID-19 restrictions are tight in Berlin, many party organisers plan events outside the capital city in the state of Brandenburg, where up to 1,000 revellers can dance to their heart's content - and without masks - at open-air festivals, so long as they show proof of a negative COVID-19 test, vaccination or having recovered.

       (Reporting by Reuters TV; Writing by Paul Carrel; Editing by Kirsten Donovan)