Ava was last seen at around 4.30pm yesterday (September 30) at Hatfield train station.

The 17-year-old is described as being 5ft 4in tall, with dark blonde hair. She was last seen wearing grey leggings, a blue hoodie and white trainers.

Ava was last seen at Hatfield train station.

Officers are growing increasingly concerned for the welfare of Ava, who also has links to Welwyn Garden City and London

Call 999 immediately if you believe you are with Ava now or have seen her in the last few moments.

You can report information online at herts.police.uk/report, via online web chat at herts.police.uk/contact, or by calling the non-emergency number 101, quoting ISR 789 30 September.