KIGALI, Rwanda – Rwandan police said Friday they had killed three suspected extremists linked to the Somalia-based group al-Shabab and thought to be part of a “radicalization campaign aimed at recruiting jihadists.”

This East African country has never been attacked by Islamic extremists, but authorities now say there is a threat of an extremist network here.

Police said the three were among six suspects, including a woman, who had resisted arrest in the western district of Rusizi.

The incident comes after police on Wednesday said they had killed a suspected extremist following a three-hour firefight in the capital, Kigali.

The presence of suspected extremists has come as a shock to many Rwandans who regard the country as an oasis of peace in a volatile region. Since last year, authorities say, they have been investigating individuals linked to foreign Islamic extremist organizations, including the Islamic State group.

“Preliminary investigations indicate that the terrorist suspects were in a radicalization campaign aimed at recruiting jihadists,” police said in a statement Friday on the latest incident.

Sano Nkeramugaba, the head of police in Rusizi, told reporters that the suspects were believed to be part of an extremist network linked to members of al-Shabab, the Somali group that frequently carries out lethal attacks at home as well as in neighbouring Kenya.

In January, Rwandan police shot dead a Muslim cleric in Kigali who was suspected of recruiting for the Islamic State group.