Abstract: A tamper evident safety closure for containers composed of an assembly of an inner cap and an outer cap, the inner cap provided with threading for screwing onto the mouth of a container. The outer cap can be depressed over the inner cap against a resilient force and the caps can be unscrewed from a container only after depressing the outer cap. A central upstanding part on the inner cap cooperates with a bridging wall portion, bridging a central opening in the top wall of the outer cap and connected thereto by a rupturable connection. There is an asymmetry in these parts so that the bridging wall portion does not rupture instantaneously all around its periphery but either remains connected to the outer cap with showing plastic deformation or ruptures gradually around its periphery or both.