Ilinca Hélène Jeanne Herr is 160-170cm tall, has long light brown hair, fair skin, and is of slim stature.
The last time the missing woman was seen, she was wearing a grey jacket, grey trousers, black and pink sneakers, and was carrying a khaki brown purse.
People with information on the potential whereabouts of the woman should contact the Luxembourg City police department via phone (244 40 1000) or email (police.LUXEMBOURG@police.etat.lu). Authorities already carried out a search for her with a helicopter and dogs on Sunday afternoon.
