This image, provided by the Seoul Metropolitan Police Agency on Dec. 15 shows a suspect withdrawing money after defrauding victims in romance schemes. Yonhap

A total of 12 foreign nationals have been arrested on charges of defrauding female victims in internet romance schemes, police said Thursday.

The suspects are accused of a wire fraud of 3.7 billion won ($2.8 million) in total against 31 victims between November of last year and October, according to the Seoul Metropolitan Police Agency (SMPA).

The suspects adopted various fake online identities to gain the victims' trust and eventually establish a relationship with them online, it said.

On one occasion, the scammers allegedly posed as American doctors or soldiers dispatched to Ukraine to manipulate the vulnerable victims, mostly middle-age women, the officers said.

Once the suspect ingratiated themselves with the women, they then allegedly concocted stories about why they needed money and asked for it, the SMPA said.

The suspects are part of a scam ring based in African nations including Nigeria and Mali, they said. (Yonhap)