An operation by Taiwanese immigration authorities on Wednesday that led to the arrests of ten illegal Vietnamese and Indonesian migrant workers in western Taichung, Taiwan, also reportedly uncovered illicit substances and weapons.

Immigration officers had received complaints regarding a galvanized iron shed in Longjing District in western Taichung. The shed was reportedly home to illegal migrant workers who held late night parties that disturbed the quiet neighborhood, the China Daily News reported.

Following months of investigations, more than 20 officers from the immigration and police departments raided the location during the early hours of April 17, where at the front door they caught a Vietnamese man surnamed Nguyen who was believed to be the in charge of the premises.

A cigarette packet that Nguyen was seen dropping to the ground was found to contain around 10 sachets of amphetamine.

Two men surnamed Pham, and another migrant also surnamed Nguyen, all Vietnamese nationals, were arrested as they tried to escape by climbing out of windows.

Six Indonesian migrant workers, one of whom was in Taiwan on a tourist visa while the others were migrant workers who had run away from their employers, were arrested for illegal overstaying.

As well as two sets of apparatus for drug inhalation, a total of 87 sachets of ketamine, a homemade bullet and a gas soft gun were recovered from the premise.

All 10 arrestees underwent urine testing, which led to four Vietnamese including the ringleader Nguyen, and one Indonesian man testing positive for drugs.

The five Indonesians who were drug-free were sent to a detention center pending their repatriation while the other five were charged with abusing drugs. The ringleader Nguyen was also charged with the possession of weapons.