Protests against a tourism development plan in the ancient Peruvian city of Cuzco have led to the suspension of public transportation and airport operations.

Local authorities and media say protesters marched through the city and used rocks and sticks to block major roads Thursday.

The trouble forced authorities to temporarily ground flights at Cuzco's airport and affected train service to the famed ruins of Machu Picchu.

Police say they provided escorts to tourists visiting Cuzco's historic sites.  Demonstrators are protesting a new law that promotes the development of tourism services near archaeological sites.

Cuzco is the site of the ancient Incan civilization and is a UNESCO World Heritage Site.  Thursday's protest is the second to hit Peru this week. On Tuesday, three people were killed in a demonstration by farmers in Ayacucho state protesting a free trade deal with the United States.

Some information for this report was provided by AFP, AP and Reuters.