By Branislav Krstic and Fatos Bytyci
MITROVICA, Kosovo (Reuters) - Serbs reinforced barricades in northern Kosovo's divided city of Mitrovica on Thursday and NATO peacekeepers were out in force, two days after 20 people were injured in clashes.
Ethnic Serbs in Kosovo's north have set up roadblocks to try to prevent the ethnic Albanian-majority government from extending its rule into Serb areas.
NATO-led peacekeepers, known as KFOR, dismantled one of those blockades at the Jarinje border crossing with Serbia on Tuesday, leading to clashes with Serb demonstrators in which at least 16 Serbs and four peacekeepers were hurt.
More incidents flared on Wednesday, and the peacekeepers have since maintained a presence on the streets. Dozens of NATO troops in armored vehicles were stationed close to the main bridge in Mitrovica and near the disputed Jarinje border crossing on Thursday.
Serbs brought trucks loaded with stones and reinforced their barricades on bridges across the Ibar river that splits the city into northern Serb and southern Albanian districts.
Northern Mitrovica's mayor Krstimir Pantic said Serbs would try to refrain from violence.
"Even if KFOR uses force we will resist it peacefully," Krstic told Reuters.
In a statement, NATO accused Serb extremists of provoking Tuesday's violence in Jarinje and said it would use force to protect its troops.
Kosovo, a former province of Serbia, became independent in 2008 after a decade of U.N. rule. NATO bombardment drove out Serbian troops in 1999, but 60,000 ethnic Serbs still live in the north of the country, loyal to Belgrade.
Kosovo is recognized as an independent state by more than 80 countries, including the United States and most of the European Union, but not by Serbia, its allies Russia and China, and some EU members including Greece, Cyprus, Spain and Slovakia.
Tuesday's clashes prompted Serbia to cancel EU-mediated talks with Kosovo in Brussels aimed at improving cooperation in areas such as the flow of goods and property rights.
The United States called on all parties "to maintain calm, to avoid precipitous actions, to refrain from inflammatory rhetoric, and allow freedom of movement."
"Roadblocks, barricades and violence only serve to impair the daily lives of the people of Kosovo and Serbia and inhibit their freedom of movement," a U.S. State Department spokesman said.
Russia, a veto-wielding member of the U.N. Security Council, said it was concerned about the violence in Kosovo and urged KFOR to maintain neutrality.
Serbia wants to join the European Union and is likely to be granted candidate status by end-October, but must mend ties with Kosovo to secure a date for accession talks.
(Writing by Aleksandar Vasovic; Editing by Peter Graff)