Malaysian authorities found 155 Muslim Uighur emigrants from China’s Xinjiang province crammed into two apartments in the capital city of Kuala Lumpur Wednesday, Reuters reported. Among them were 76 children. All have been detained at Kuala Lumpur International Airport’s Immigration Detention Depot pending further investigation.

Acting on a tip, Malaysian Immigration Department officers found 90 people in one apartment and 65 in the other apartment, Reuters said. The immigrants were carrying Turkish passports, which authorities believe to be fake.

“We had not expected to see so many of them in one unit,” Reuters quoted one immigration officer as saying. “We are trying to determine where they came from and where they are headed. As of now, we are uncertain whether they entered the country illegally or through the proper channels.”

China’s restive northwestern Xinjiang region has witnessed spiraling violence for years now, with people protesting against the Chinese central government. Xinjiang’s regional government has said separatists want their own state called Turkestan, while some Uighur groups and human-rights activists have said Beijing has provoked the unrest by its controls on Islam and other policies in Xinjiang.

Last month, there were a series of explosions in Xinjiang that killed at least 50 people. In June, China executed 13 people for terrorist attacks and violent crimes there.