Officers are concerned for the welfare of two teenagers who have been missing for three days. Koibilo Ransom-Kuti (also known as Koby) and Scarlett Antigua-Noble were last seen in Gravesend town centre on Friday (March 1). Koby, 15, is described as being five feet and eight inches tall, of slim build and with black hair. He was wearing his school uniform – dark trousers, navy blue blazer, white shirt and black shoes – along with a light grey hooded top. He was also carrying a red Nike backpack. Scarlett, 14, is five feet and eight inches tall, of slim build and with dark hair. She was last see…