The United States authorities said eight persons have been arrested for alleged roles in an Africa-based cyber conspiracy that law enforcement officials say defrauded companies and citizens of millions of dollars.

Five of the defendants – a Mexican, two Americans, a Ghanaian and a Nigerian – were arrested in the U.S., the Justice Department said.

The other three; two Ghanaians and a Nigerian were arrested outside the U.S. and were being held pending extradition.

The arrests were made as part of the department’s efforts to fight schemes to intercept wire transfers from businesses and individuals.

Speaking on the case, Acting Assistant Attorney-General, John Cronan said,

“The defendants allegedly unleashed a barrage of international fraud schemes that targeted US businesses and individuals, robbing them to the tune of approximately 15 million dollars.”

The indictments are part of Operation Keyboard Warrior, a recently announced effort coordinated by U.S. and international law enforcement to disrupt online frauds perpetrated from Africa.

The Africa-based co-conspirators committed a series of intrusions into the servers and email systems of a Memphis-based real estate company in 2017, according to the indictment.

The defendants were able to use spoofed email addresses and other anonymisation techniques to identified large financial transactions and initiated fraudulent email correspondence with relevant business parties.

They then redirected closing funds for real estate transactions to destinations in Africa. The indictment includes charges related to wire fraud, money laundering, computer fraud and identity fraud.

Some of the Africa-based defendants are also charged with operating romance scams, fraudulent-check scams, gold-buying scams and credit card scams.