A closure (3) for a container (1), the container having a mouth (16) surrounded by an external flange (7) extending generally away from the mouth, the closure comprising a closure body (9) adapted to extend across the mouth, a skirt (15) which is disposed below the level of the container flange when the closure is initially secured to the container and the mouth is uppermost, the skirt being connected to the margin of the body by a plurality of spaced-apart bridges (19) which lie adjacent to the outer margin of the flange in the initially secured condition of the closure, and a plurality of upwardly-facing latching formations (20) depending from the skirt (15) and each disposed circumferentially between adjacent bridges (19) as viewed in plan and adapted to latch under the flange (7), the upper portion (23) of the latching formations each lying vertically beneath a respective tool access aperture (25) provided in the margin of the closure body. The tool access apertures (25) enable the closure to be thermo-formed from sheet plastics material on a two-part tool assembly.