Driving a delivery van with stolen post office licence plates and decals the robbers showed false identification papers to get past a security gate and enter the inner courtyard of the post office at 10:37 a.m., law enforcement officials said.
Using handguns to hold postal workers at bay the robbers grabbed several containers of cash from a loading dock. No one was hurt, and the robbers quickly disappeared in Zurich streets, police said.
Investigatos said the robbers probably had elaborate inside information on security procedures.