Airbag and method of manufacturing an airbag

An airbag (12) of a vehicle occupant restraint system (10), comprising plural juxtaposed compartments (16) delimited outwardly by opposing external walls (18) and against each other by partitions (20), wherein the airbag (12), when in the inflated condition, has an overall bent elongate form in cross-section, wherein in the bending area one of the opposing external walls (18) includes a cut-out (22) which is closed by an inserted insert comprising a panel (24) that is tensioned in the deployed condition and that has in the bending area a length (LE) different from an opposing external wall portion (28) so as to produce the bending, the panel (24) including a first edge portion attached to the one of the opposing external walls (18) along a first edge of the cut-out (22) and a second edge portion attached to the one of the opposing external walls (18) along an opposing second edge of the cut-out (22).