An American woman vacationing in Belize has been reported missing, authorities in the country said.

Alison MacKenzie, 43, was on an overnight catamaran tour with more than a dozen other passengers, including a male friend, when she vanished. A spokesperson for the Belize Police Department said they received the missing persons report around 6 a.m. on Saturday from someone who said they woke up earlier that morning to find that MacKenzie was gone.

Alison Mackenzie. via Facebook

The catamaran tour, which is operated by Ragamuffin Tours, left the island of Caye Caulker on Friday for Rendezvous Caye, the company said in a press release. Fifteen passengers and three crew members were on the tour.

The company said it is "cooperating fully with law enforcement officers in their investigation into this incident."

"Ragamuffin Tours Limited is operated by a Caye Caulker family and as a family, we are deeply distressed and concerned as to the whereabouts and well being of Alison Mackenzie," the statement read. "We are in contact with and have offered our full cooperation to the family of Alison Mackenzie, and we assure them that we will continue to do all in our power to assist law enforcement in their investigation into her disappearance."

The U.S. State Department told NBC News in a statement that it is aware that MacKenzie has been reported missing.

"The welfare and safety of U.S. citizens abroad is one of the highest priorities of the Department of State," the spokesperson said. "Whenever a U.S. citizen is missing, we work closely with local authorities as they carry out their search efforts, and we share information with their family however we can. Due to privacy considerations, we have no further comment at this time."