(adds grenades, details from EU police statement)
MITROVICA, Kosovo, April 27 (Reuters) - European Union police used teargas on Monday to disperse Serbs protesting at the return of Albanian refugees in northern Kosovo and the protesters threw two hand grenades, officials said.
Hundreds of Kosovo Serbs have staged rallies against the construction of seven destroyed houses belonging to Albanian returnees near the flashpoint town of Mitrovica.
"There were a number of minor injuries and two hand grenades were thrown at EULEX (EU police and justice mission) officers and NATO troops," EULEX said in a statement.
"Shots were also fired in the direction of police officers from the European Union and those engaged in construction work."
Earlier, the EU police officers used tear gas and stun grenades to disperse 100 protesters.
"When there is violence or people trying to cross the Kosovo police line, then EULEX is going to intervene," said EULEX spokesman Christophe Lamfalussy.
NATO peacekeepers and police have stepped up their security presence in the town of Mitrovica. NATO armoured vehicles were patrolling in the area.
A river running through Mitrovica divides the town into largely Serb and largely Kosovo Albanian halves, and few local residents cross the bridges to the other side.
Kosovo declared independence from Serbia in 2008 but the 120,000 remaining Kosovo Serbs have refused to cooperate with Albanian-run institutions. (Reporting by Fatos Bytyci and Branislav Krstic, editing by Adam Tanner and Robert Woodward)