The UN refugee agency sought access to five ethnic Uighur Chinese arrested in Malaysia amid criticism by rights activists Tuesday over the country's deportation of 11 others to China.
Malaysian authorities said all 16 were detained this month on suspicion of human trafficking.
The minority Uighurs (pronounced WEE-gurs) repatriated to China from elsewhere in the past have expressed fears of long jail terms or the death penalty.
The UN High Commissioner for Refugees' office in Kuala Lumpur voiced regret Tuesday that Malaysia deported 11 last week without allowing them access to UN officials.
UNHCR was seeking access to the remaining five in detention "to assess their conditions and to finalize our review of their claims for asylum," Yante Ismail, a UNCHR official based in Kuala Lumpur, told The Associated Press.
"We had expressed our opinion to the government of Malaysia that if indeed they had committed criminal offenses, that they undergo fair legal process in Malaysia and not be deported to a country where their lives or freedom may be at risk," she said.
Representatives for Malaysia's Home Ministry, which handles police and security issues, said they could not immediately comment on the Uighurs.
Malaysia's deputy national police chief, Khalid Abu Bakar, said last week the action against the Uighurs was part of "stern measures that must be taken to send a message to human trafficking syndicates."
The suspects had smuggled other Chinese citizens into Malaysia through neighboring Thailand and provided them with forged immigration documents to travel to other countries, Khalid said.
Phil Robertson, deputy director the New York-based Human Rights Watch's Asia division, said the deportation of the 11 was "the latest in a coordinated campaign by the Chinese government against the Uighurs, who in the past month have been bundled off to China by officials in Thailand, Pakistan and now Malaysia."
"The Malaysian police accused these Uighurs of being people smugglers or traffickers, but then threw legal due process out the window" by deporting them instead of charging them under Malaysian law, Robertson said in a statement to the AP.
Human Rights Watch added that the Chinese government should account for what has happened to the 11 deported.
China has said that some Uighurs — a Muslim minority from the restive western region of Xinjiang — are terrorists or criminals who pose a threat to the region's safety, and has previously insisted that Uighur refugees be extradited back.
Overseas Uighur activists and analysts say anger among Uighurs over government economic policies and restrictions on their culture, religion, and language has helped drive an upsurge in violence in Xinjiang in recent years.
UNHCR did not manage to verify the identities of the 11 deported by Malaysia last week or whether they had formally sought asylum, but police have said the remaining five possess identification cards issued by UNHCR.