NATO calls for peace between Kosovo and Serbia.

NATO chief Jens Stoltenberg has called on Kosovo to de-escalate tensions with Serbia after clashes between Kosovan police and protesters who are opposed to Albanian mayors taking office in ethnic Serbian areas. Serbia's President Aleksandar Vucic ordered the army to be placed on high alert and "start moving" towards the border with Kosovo. The US, UK and EU are Kosovo's main backers as the country is still not a United Nations member due to objections from Serbia, Russia, China and others.