Image copyright Lucie Blackman Trust Image caption Catherine Shaw had previously visited Mexico and California

The family of a 23-year-old British woman missing in Guatemala say they are "desperately worried" for her safety.

Catherine Shaw, from Witney, Oxfordshire, had been travelling and was reported missing on 5 March.

She was last seen the day before and had been staying in the San Pedro, Lake Atitlan area of the central American country with a friend, the Lucie Blackman Trust said.

Her parents Ann and Tarquin said her disappearance was of "great concern".

"She has always been really good about keeping in touch and informing us of her whereabouts and activities," they said in a statement released through the trust.

"So this is unusual behaviour which gives us great concern for her safety. Please help us to find her."

Ms Shaw has been travelling since September and had previously visited Mexico and California.

A Foreign Office spokeswoman confirmed it was supporting the family of a British woman and were "in contact with the local authorities as they search for her".

In a video posted on Twitter by the trust, her mother urged her to get in touch, while her father added: "Your friends, your family are all really worried about you, please come home sweetheart."

Trust chief executive Matthew Searle said the "first few days are vitally important" because those who may have seen something could still be in the area.

"We urge anyone who may have any information, no matter how small, to get in touch as soon as they can," he said.

"They could hold the key to bringing Catherine home."

Social media appeal

The trust, which provides support for the families of people who go missing while abroad, said Mr Shaw was travelling to San Pedro to join the search with volunteers in the area.

Ms Shaw's friends have launched a social media fundraising appeal, raising more than £2,600 so far to support the search.

Jess Elizabeth wrote an impassioned plea on Facebook asking for help to find "our best friend".

She said Ms Shaw had "no belongings with her, passport money or mobile phone - they were left at the hostel".

Jennifer Shaw appealed: "Please please please if anyone has any connections in Guatemala which could help find my sister, she has been missing since Monday."

Hotel Mayachik in Lake Atitlan said Ms Shaw was seen on their security cameras leaving the hotel at 01:37 (local time) on Tuesday carrying a musical instrument.