CAIRO, May 31 (Reuters) - Four Mexican tourists were killed and 17 were injured, two of them critically, in a bus accident on Friday in Egypt's Sinai Peninsula, the governor of South Sinai said.

The tourists were travelling on a bus owned by a local tour company near Saint Catherine's monastery in central Sinai when their bus overturned and caught fire, medical and security sources said.

At least 40 tourists, all from Mexico, were inside, the state news agency MENA reported.

The injured tourists were transferred to three hospitals in the area, governor Khaled Fouda said. He said they had been traveling to the monastery, a popular tourist destination, from the town of Taba, which borders Israel.

The 2011 uprising that ousted President Hosni Mubarak and the turmoil that followed has dentedEgypt's tourism sector - a major employer and source of foreign currency which accounted for more than 10 percent of gross domestic product.

The sector has been further damaged by kidnappings in Sinai and high-profile accidents, including a hot air balloon crash near Luxor in February that killed 19 tourists, most of them Asian and European. (Reporting by Youssry Ahmad; Writing by Maggie Fick; Editing by Sonya Hepinstall)