By Fatos Bytyci

PRISTINA (Reuters) - Police fired teargas in Kosovo on Monday to disperse opposition activists demonstrating against a new push by the European Union to improve ties between Serbia and its former southern province.

The clashes, in which 18 police officers were injured, followed a meeting last week in Brussels between Kosovo Prime Minister Hashim Thaci and his Serbian counterpart, Ivica Dacic.

It was the first meeting at such a level since majority-Albanian Kosovo declared independence in 2008.

The EU says the two must normalize relations and solve a range of practical problems arising from Serbia's refusal to recognize Kosovo if they are to make further progress towards membership of the bloc.

But hardliners in Kosovo say they have nothing to discuss with Serbia, which was bombed by NATO in 1999 to halt the killing and expulsion of ethnic Albanians by Serb forces under late strongman Slobodan Milosevic during a two-year counter-insurgency war.

Up to 200 activists of the opposition Vetevendosje (Self-determination) party tried to blockade Thaci's office in protest at his meeting with Dacic, who was Milosevic's wartime spokesman.

Police drove them back with pepper spray and teargas. The protesters pelted officers with stones, police said.

"This was a shameful meeting (in Brussels)," said Vetevendosje deputy leader Shpend Ahmeti. "After all the crimes in Kosovo, no one has taken responsibility or apologized."

The party said several activists were beaten by police and treated in hospital.

EU-mediated talks are expected to resume in November, focusing on a range of practical problems arising from the lack of diplomatic relations, such as energy supplies, a telephone country code for Kosovo and management of their joint border.

The most contentious issue will be Kosovo's north, a mainly Serb-populated region propped up by Belgrade in a de facto ethnic partition of the country.

The EU, which made Serbia a candidate for membership of the bloc in March, wants Belgrade to loosen its grip on the north, but the Serbs there refuse to have anything to do with Thaci's government in Pristina and function largely as part of the Serbian state.

Kosovo has been recognized by more than 90 countries, including the United States and 22 of the EU's 27 members.

Serbia, backed by U.N. Security Council veto holder Russia, says it will never recognize the territory of 1.7 million people as sovereign.

(Editing by Matt Robinson and Patrick Graham)