A group of 20 Chinese Uighurs who fled to Cambodia after ethnic riots in July have been deported back to China, BBC reported.
The United Nations refugee agency strongly condemned the deportation, saying Cambodia had committed a grave breach of international refugee law.
The decision follows intense pressure by China, which has referred to the group as criminals.
Human rights groups have warned that the group is likely to face persecution on return to China.
The expulsions came ahead of a visit to Cambodia by Chinese Vice-President Xi Jingping on Sunday. There has been no immediate comment from the Chinese foreign ministry.
A protest by Uighurs in the city of Urumqi, in Xinjiang region, erupted into violence in July, leaving at least 197 people dead.
Shops were smashed and vehicles set alight while passers-by were set upon by Uighur rioters in the city, whose population is mostly from China's dominant Han group.
Groups of Han later went looking for revenge as police struggled to restore order.
Most of those killed in the unrest were Han, according to officials, and Urumqi's Han population had demanded swift justice.
Twelve people were sentenced to death after the riots.
Tensions between the mainly-Muslim Uighurs of Xinjiang and Han have been growing in recent years. Millions of Han have moved to the region in recent decades.
Many Uighurs want more autonomy and rights for their culture and religion than is allowed by Beijing's strict rule.