A Malaysian human rights group called on the government Sunday not to forcibly deport 155 Chinese ethnic Uighurs reported to be in the country illegally, amid concerns for their fate in China.

Malaysian media reported Friday that the Uighurs, including 76 children, were found in a pair of cramped apartments in the capital Kuala Lumpur in a raid two days earlier by immigration authorities.

The Malaysian government, which has sought closer trade ties with Beijing, came under criticism 18 months ago from international human rights groups and the UN refugee agency for sending six Uighurs back to China in an earlier case.

Malaysian rights group Suaram said there was concern that deporting the Uighurs "might put their life at risk, especially since there are 76 children involved."

Malaysia is not a signatory to the UN's key refugee treaty, but the government is bound by international principles against deporting "persons to places where they may face persecution," Suaram said.

Uighurs are a Turkic-speaking and predominantly Muslim minority in China's remote northwestern Xinjiang region. Many allege decades of political and religious repression by China.

Xinjiang tensions have soared amid a wave of violence over the past year, including deadly attacks on civilians, which China blames on "terrorists".

A Malaysian immigration department official reached Sunday by AFP declined comment.

Malaysia is a major transshipment point on regional refugee and people-smuggling routes.

Authorities in Muslim-majority Malaysia have expressed growing alarm over reports that scores of its citizens had gone to Syria to take part in its civil war, prompting fears they could join the radical Islamic State group and import extremist ideas on their return home.

Similar fears have been expressed in neighbouring Indonesia.

Indonesian police said in mid-September that they had arrested four Uighurs suspected of being linked to the Islamic State.

Suaram said any detained Uighurs should have their cases adjudicated by Malaysian courts, and urged the government to work with the UN High Commissioner for Refugees (UNHCR) on the matter.

A UNHCR spokeswoman told AFP the agency was still seeking information from authorities on the report of the 155 Uighurs and declined comment.

Malaysia deported six Uighurs in December 2012 while the UNHCR was processing their refugee claims, sparking an outcry.

It deported an earlier batch of 11 Uighurs in 2011, saying they were involved in a human-smuggling syndicate.