They said Monday that explosives, weapons and ammunition of various caliber were seized in the major police operation.

The 40 men were being questioned on suspicion of engaging in acts against Kosovo's constitutional order and endangering the safety and security of the state, a police statement said.

Local media said an 18-year-old man from eastern Kosovo was killed in Syria last week, raising the total number of Kosovo Albanians killed in Iraq and Syria to 16.

A Kosovo intelligence source who asked not to be identified said an estimated 100-200 citizens were believed to have gone to Syria and Iraq for the purpose of combat so far.

Kosovo's parliament is expected to pass legislation soon banning citizens from joining foreign insurgencies, with a maximum sentence of 15 years in prison on conviction.

A number of European countries including Britain, France and the Netherlands have begun cracking down on citizens, going to join extremist terrorists in Syria and Iraq.

They are concerned that such volunteers could eventually return to Europe battle-hardened, radicalized and posing security threats.

Kosovo gained independence from Serbia in 2008 after a bloody uprising in the late 1990s.

NTJ/MB