People walk on the road by a barricade near the village of Rudare, in the north of the Serb-dominated part of ethnically divided town of Mitrovica, Kosovo, on Dec. 11.Bojan Slavkovic/The Associated Press Tensions were high in northern Kosovo on Sunday, with Serbs blocking roads as shots and explosions rang out overnight, Kosovo police and media reported Sunday. No injuries were reported. The blocking of the roads with heavy vehicles and trucks happened a day after the Serbian president said he would ask the NATO-led peacekeeping force in Kosovo to permit the deployment of 1,000 Serb troops in the Serb-populated…