Nigeria’s anti-graft agency said it had arrested 792 suspects in a raid on a building believed to be a hub for fraudsters who lured victims with offers of romance, then pressed them to hand over cash for phoney cryptocurrency investments.

The suspects, including 148 Chinese and 40 Filipino nationals, were detained on Dec. 10 at the seven-storey Big Leaf Building in Lagos, Nigeria’s commercial capital, Economic and Financial Crimes Commission spokesperson Wilson Uwujaren said.

The luxury building housed a call centre mostly targeting victims from the Americas and Europe, he added.

Staff there would make contact with people through social media and messaging platforms, including WhatsApp and Instagram, them seduce them online or offer them apparently lucrative investment opportunities.

Once victims were hooked, they were pressured to transfer money for fake cryptocurrency schemes and other non-existent projects.