The US State Department has joined in the search for an American couple who disappeared in Peru, Fox News reports.
Garrett Hand and Jamie Neal left the Bay Area of California in November on a biking expedition across South America.
The pair had been chronicling their adventures with regular status updates and photos on Facebook but the messages stopped on January 25.
"It's upsetting, I'm worried about both of them," Jeff Jerge, owner of Pedaler Bike Shop where Neal worked told KTVU.
The couple were last seen on Jan 26 getting into a cab in Lima after taking a bus from Cusco.
One of Neal's last updates said the couple had decided to go to the Amazon instead of Machu Picchu, reports KTVU.
Max Hunter, a friend of the couple, told the Seattle Times that the couple's credit cards abruptly stopped being used that same day.
"Originally I was hoping that they were stuck in a remote area for the last month and unable to get in touch, maybe due to mechanical trouble with their bicycles," he said.
"However, since the last sighting places them in Lima, this seems unlikely."
The State Department made a poster of Neal and Hand and the US Embassy in Peru sent out a travel warning about a potential kidnapping threat, reports Fox.
"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," the statement said.
"Possible targets and methods are not known and the threat is credible at least through the end of February 2013."