The National Bureau of Investigation (NBI) on Friday reported that its operatives apprehended at least 79 Chinese nationals during a raid on a factory at San Jose del Monte in Bulacan last Thursday.

In a statement, the NBI-Bulacan District Office disclosed that the operation was launched after receiving intelligence reports of illegal foreign workers at a factory in Sitio Complex, Barangay Sto. Cristo.

Agents from the Bureau of Immigration (BI), Regional Intelligence Unit 3, and Clark Special Economic Zone joined the raid.

Of the 79 detained Chinese, 36 were undocumented while 23 held only tourist visas, officials said. Six company officials were also taken into custody.

The group was transported to NBI headquarters in Quezon City for questioning. The factory allegedly manufactures water pipes for a water concessionaire.

“We have some people with legal working permits, and some are in the process of applying for the permit,” a Chinese translator among those detained said.

NBI director Jaime Santiago expressed concern over the large number of undocumented foreign workers.