The two Chinese Uygurs are members of the East Turkestan Islamic Movement, which is listed as a terrorist group and sanctioned by the United Nations, Foreign Ministry spokesman Liu Weimin said at a press briefing.
China has lodged solemn representation to the United States on the transfer of the two detainees from the Guantanamo detention camp to El Salvador, he said.
"China always resolutely opposes the US releasing Chinese terrorist suspects on its land or transferring them to a third country, and it opposes any third country taking them in any name, " Liu said.
According to relevant UN resolutions, all countries should refuse to provide secure shelter to those who have funded, planned or implemented terrorist activities, and they should also refuse to provide shelter to terrorist actions or personnel, Liu said.
"We urge the US to correct its mistakes, and hope El Salvador could be clearly aware of the danger of those suspects, attach importance to China's concern, implement international obligation and refuse to accept those suspects," he said.