On the evening of Saturday, 27 March 1943, nine members of a resistance group attacked the Amsterdam population register. Dressed as police officers, they overpowered the guards. The resistance people opened the filing cabinets, threw the papers on the floor and poured a combustible liquid onto the pile. They then placed explosives and left. Shortly thereafter, five explosions were heard, and a large fire broke out, which could be seen from afar.
The attackers belonged to a resistance group that produced false identity cards. Because of the risk that these forgeries would be detected if the data were checked against the population register, that group had tried to destroy the register.