A British tourist has mysteriously vanished while on a solo trip to the US. The 21-year-old was reportedly meeting a mystery man carrying flowers at the airport before her phone suddenly went dead.

Katherine Esther Gamboa Kerwood travelled to California for what was meant to be a week-long sightseeing break but alarm bells were raised when her family, from Portsmouth, discovered she had never checked into the hostel where she claimed she was staying. The she was last seen on CCTV at San Francisco International Airport with a man who she first met in the UK, as reported by NeedToKnow. The missing woman was last heard from on Friday when she sent a text message to loved ones. But when worried relatives asked to speak to her on the phone, she allegedly stopped responding altogether. Loved ones have since stated that it is unusual for her to go quiet and not update them.

Kerwood arrived at San Francisco International Airport on March 31 and had planned to visit several locations during her trip, including Sacramento, Calaveras Big Trees State Park, San Francisco and Santa Cruz.

Her family said she told them on Tuesday that she was staying at a hostel in Sacramento.

However, they later discovered she had never checked into the accommodation.

The circumstances surrounding her disappearance remain unclear.

Police in San Francisco have now launched a search for the 21-year-old amid growing concern for her welfare.