Two hand grenades were thrown into the compounds of the United Nations and the European Union in the Kosovo Serb stronghold city of Mitrovica on Monday, after Kosovo announced independence from Serbia earlier in the day.

One of the grenades exploded, but the explosion caused no major damage, news reports said.

EU officials were evacuated from the compound after the explosion, and local police were investigating the case.

The NATO-led peacekeeping force KFOR in Kosovo are now on high alert on possible clashes between local majority Albanians and minority Serbs.