Visitors walk at the Inca citadel of Machu Picchu in Cusco, Peru, August 12, 2015. REUTERS/Pilar Olivares

LIMA (Reuters) - PeruRail, the company that takes hundreds of thousands of foreign visitors to the ancient Incan ruins of Machu Picchu each year, suspended service indefinitely on Thursday due to the threat of violent protests.

PeruRail said in a statement it would run a few trains to evacuate tourists who are already at the site, one of South America’s most popular tourist attractions, and will refund tickets that have been purchased.

A group, known as the Unique Front to Defend Machu Picchu, began protesting in the area earlier this week, demanding better service.

“Private enterprise cannot continue to push around Peruvians and visitors of the world,” the mayor of Machu Picchu town, David Gayoso García, said in a post on Facebook.

Peru’s capital, Lima, is hosting global leaders attending the Asia-Pacific Economic Cooperation summit, some 600 kilometers away.