Myanma women are increasingly transported to China and subjected to sex trafficking; Myanma government officials are occasionally complicit in this form of trafficking, as well as in the facilitation of the smuggling and exploitation of Rohingya migrants. Myanmar is a major source of prostitutes (an estimate of 25,000–30,000) in Thailand, with the majority of women trafficked taken to Ranong, bordering south Myanmar, and Mae Sai, at the eastern tip of Myanmar. Myanma sex workers also operate in Yunnan, China, particularly the border town of Ruili. The majority of Burmese prostitutes in Thailand are from ethnic minorities. Sixty percent of Burmese prostitutes are under 18 years of age. The United States Department of State Office to Monitor and Combat Trafficking in Persons ranks Myanmar as a 'Tier 3' country.