U.S. Secretary of State Marco Rubio on Thursday condemned Thailand's return of at least 40 Uyghurs to China, where Washington says members of the Muslim group have faced genocide.

Human rights groups warned that the Uyghurs, who were held in Bangkok for more than a decade, will face mistreatment from Chinese authorities back in Xinjiang.

At least 40 Uyghurs have been deported to China,Thai authorities have confirmed, despite warnings from rights groups they could face possible torture and even death. The group is thought to have been flown back to China's Xinjiang region on Thursday, after being held for 10 years in a Bangkok detention centre.