The government of Niger has deactivated a third of mobile phone connections in the country in a bid to curb criminal activity using unregistered SIM cards, according to local reports.

Unregistered SIM cards account for 1.7 million of Niger’s 5.4 million mobile connections, according to Agence France-Presse (AFP). These mobile phone connections are often used for criminal activity and in 2012, Niger’s authorities reportedly mandated that subscribers register with their mobile operator in a bid to halt such activity.

“From today, non-registered SIM cards can no longer be used,” Almoustapha Boubacar, director-general of regulator CSC told the agency.

The agency added that Niger is often targeted by terrorist groups from Mali and Nigeria due to the nation’s poor border security.