A Zambian court has sentenced 22 Chinese nationals to long prison terms for cyber crimes that included internet fraud and online scams targeting Zambians and people from Singapore, Peru and the United Arab Emirates.

The magistrates’ court in the capital, Lusaka, sentenced them to prison terms ranging from seven to 11 years.

The court also fined them between 1,500 and 3,000 dollars (£1,175 to £2,350) after they pleaded guilty to charges of computer-related misrepresentation, identity fraud and illegally operating a network or service on Wednesday.

A man from Cameroon also was sentenced and fined on the same changes.

They were part of a group of 77 people, the majority of them Zambians, arrested in April over what police described as a “sophisticated internet fraud syndicate”.

Director-general of the drug enforcement commission, Nason Banda, said investigations began after authorities noticed a spike in the number of cyber-related fraud cases and many people complained about inexplicably losing money from their mobile phones or bank accounts.

Officers from the commission, police, the immigration department and the anti-terrorism unit in April swooped on a Chinese-run business in an upmarket suburb of Lusaka, arresting the 77, including those sentenced on Friday.

Authorities recovered over 13,000 local and foreign mobile phone SIM cards, two firearms and 78 rounds of ammunition during the raid.

The business, named Golden Top Support Services, had employed “unsuspecting” Zambians aged between 20 and 25 to use the SIM cards to engage “in deceptive conversations with unsuspecting mobile users across various platforms such as WhatsApp, Telegram, chat rooms and others, using scripted dialogues”, Mr Banda said in April after the raid.

The locals were freed on bail.