As the United States continues its recent military campaign against the Islamic State (IS) in Iraq, some jihadist fighters are returning home to Europe.
On Monday, police in Kosovo arrested 40 alleged Islamic radicals suspected of fighting in Iraq and Syria.
"We believe these persons pose a threat to Kosovo's security and they have therefore been arrested," police spokesman Baki Kelani told The Associated Press on Monday.
"Some are suspected of being involved in terrorist organizations such as ISIS and [Jabhat] al-Nusra."
Weapons, ammunition, and explosives were also seized at 60 locations across Kosovo, including makeshift mosques believed to have served as recruiting centers.
The Kosovo government applauded the police operation.
"Any threat against the fundamental values of our state and our society will be punished without mercy," one government statement said.