UPDATE: An American couple that had gone missing in Peru has been found, Peru's Ministry of Tourism and Commerce told CNN Tuesday. 

A young California couple is missing in Peru, and now their families fear they may have been kidnapped.

Garrett Hand and his girlfriend, Jamie Neal, were on what they called “the trip of a lifetime,” biking through South America. The 25-year-olds carefully planned the months-long trip and kept their families posted on their Facebook pages, adding pictures and updates as they traveled.

But the last post from the couple was on January 25 from the town of Cusco, Peru.

Jamie wrote, “Finally found Kraft Mac ‘n’ cheese in South America! Stoked LOL.”

Everything seemed fine. The couple was supposed to ride from Cusco to Lima, the capital of Peru. But more than a month later, no one has seen or heard from either Garrett or Jamie.

Jamie’s sister, Jennifer, tells HLN affiliate KTXL, “I haven’t seen a video of her (Jamie) since January 25th. So to me anything could have happened since then.”

Jennifer goes on to tell KOVR, “I just have this nasty gut feeling that something is wrong.” She fears the worst saying, “They’ve been kidnapped or either being held or something even more terrible has happened.”

Her fear isn’t unfounded. Just weeks ago, the U.S. Embassy in Lima posted a security warning for the Cusco area. 

“The U.S. Embassy warns U.S. citizens of a potential kidnapping threat in the Cusco area. The Embassy has received information that members of a criminal organization may be planning to kidnap U.S. citizen tourists in the Cusco and Machu Picchu area. Possible targets and methods are not known and the threat is credible at least through the end of February 2013.”

The U.S. Embassy is working with Peruvian authorities to try and find Garrett and Jamie. There are fliers posted in both Spanish and English, and a reward has been offered for any information.

The Hand family has also started a Facebook page to pass along any information and spread the word about the missing couple.