The detainment of the men may distract from Kosovars who do not want a UN peacekeeping mission replaced, a security expert says.
Obrad Savic targets the next generation with a message about breaking accepted Balkan stereotypes.
Despite Russian and Serbian opposition, UN Secretary-General Ban Ki Moon said Friday the UN would gradually cede its role.
The document, signed Sunday, is seen as key to stability. But many issues remain unresolved.
'I feel nothing bad about Albanians,' he says. 'A man should be judged by his soul, not his nationality.'
On Sunday, Serbs will weigh in on whether to pursue a pro-European Union path or a more nationalistic, anti-Western route.
Russia is sending humanitarian supplies worth $1.7 million directly to Kosovo Serbs, challenging the authority of the US-backed government in Pristina.