NATO said in a statement Sunday that tensions are on the rise in the northern municipalities of Kosovo and that Kosovo Force Pristina (KFOR) was monitoring the situation closely. Tensions are again on the rise amid a new government regulation that will compel people entering Kosovo with Serbian IDs to replace them with a temporary document during their stay there. On Sunday, ethnic Serbs in northern Kosovo — a partially recognized state bordered by Serbia in the Balkans — blocked two key border crossings with Serbia to protest the new rule.