PERU (CNN) -- It was the trip of their dreams: to tour South America riding their bicycles. Jamie Neal and Garret Hand, a couple from the San Francisco area, left last November and began chronicling their trip on social media.
In late January, however, their Internet postings stopped and calls to their cell phones went unanswered. Jamie Neal's sister Jennifer says the couple's families and friends haven't been able to get in touch with them since then.
"I haven't seen a video of her since January 25th, so to me anything could've happened since then, you know? I hope that she's just having a blast and that they're doing what they went to do," Neal told CNN affiliate KTXL in Sacramento, California.
Neal and Hand, both 25 years old according to a family flyer, were last seen in Lima, the Peruvian capital. But some of the areas they planned to visit are out of cell phone and Internet reach.
In fact, the Peruvian National Police told CNN that the manager of a hostel in Pucallpa where the couple stayed confirmed to a police investigator they reached the city in the Peruvian jungle in early February.
The manager of Arco Iris Amazonica, a small hotel in the rain-forest city of Iquitos, told police the couple lodged there on February 16 and told him they planned to travel by river to the town of Naplo, a 15-day trek.
Miguel Wesly, a tourism official in the Cusco region, told CNN affiliate America TV that his agency is also investigating.
"We're going to verify the information. Internet reports are not always reliable. We're going to verify if the Peruvian National Police has any news as well as the tourism police and the tourism investigations agency. There are no formal communications yet," Wesly said.
Peru is known for the Inca ruins of Machu Picchu, located in the Cusco region, which attract hundreds of thousands of international travelers each year.
Two weeks ago the U.S. Embassy in Lima issued a security message warning Americans 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," the message said.
But it also clarified that "thousands of U.S. citizens routinely travel to the Cusco region without undue incident. The U.S. Embassy remains confident of the Peruvian government's efforts to ensure the safety of all tourists in the region."
An official with the U.S. Embassy in Lima told CNN they're aware Jamie Neal and Garrett Hand are missing and they have been in communication with their families since late January.
Leslie Goodman, a spokeswoman with the embassy, said "officers with the embassy have been in touch with Peruvian authorities and the embassy is providing all appropriate consular assistance to find the couple."