Herts police have released images of a young female and are concerned for her welfare.
Chi Thi Linh Le, aged 17, was reported to have left her home address at around 2pm on Saturday 4 February.
She is around 5ft 4ins tall, of slim build with shoulder-length dark brown hair and brown eyes.
Chi Thi has links to the Euston area of London.
The CCTV images of Chi Thi were taken just after 3.30pm at Elstree and Borehamwood Station on Saturday 4 February.
Officers are concerned for her welfare.
If you have information you can report this by quoting ISR 770 of 4 February when: