PRISTINA, Kosovo — Aug 11, 2014, 6:26 AM ET

By NEBI QENA Associated Press
Associated Press

Kosovo police on Monday arrested at least 40 people in a major operation targeting Islamic radicals suspected of fighting alongside extremists in Iraq and Syria.

Spokesman Baki Kelani said weapons, ammunition and explosives were seized as hundreds of police officers and special police units raided 60 locations across Kosovo, including makeshift mosques believed to have served as recruiting centres.

The police operation is the largest ever against suspected Islamic radicals in Kosovo. Authorities have been on alert as a growing number of ethnic Albanians have joined militants in Syria and Iraq and appeared on social media in attempts to lure more followers.

"We believe these persons pose a threat to Kosovo's security and they have therefore been arrested," Kelani told The Associated Press on Monday. "Some are suspected of being involved in terrorist organisations such as ISIS and (Jabhat) Al-Nusra."

The Islamic State group, also known as ISIS, has gained territory in surprise operations in Iraq and Syria and its rise led U.S. President Barack Obama to authorize limited airstrikes against the group.

Police in Kosovo say at least 16 Kosovars who joined the militant group as volunteers have been killed in battles with Syrian and Iraqi authorities. Kosovo's ethnic Albanians are overwhelmingly Muslim.

Kosovo's government welcomed Monday's operation and warned it will fight religious extremists in Kosovo.

"Any threat against the fundamental values of our state and our society will be punished without mercy," a government statement said.

President Atifete Jahjaga said the operation seeks to bring to justice suspects whose acts threaten security in the Balkan region and to prevent "terrorist threats to Kosovo and its strategic allies."

"Kosovo will not be a safe haven for extremism," Jahjaga said.