The ex-policeman, along with other ethnic Serbs working as law enforcers in Kosovo, quit his post in mid-November. Pantic was arrested earlier on Saturday at the Jarinje border crossing.
According to the reports, local residents have gathered at the entrance and exit of the village of Leposavic, while several hundred assembled in Rudare and Srbovac. People are building barricades, the newspaper says.
Air raid sirens are sounding in northern Kosovska Mitrovica, media report.
The administration of Serbian President Aleksandar Vucic announced his address to citizens at 7 p.m. local time (18:00 GMT) on Saturday.
On Friday, Russian Ambassador to Serbia Alexander Botsan-Kharchenko said that Kosovar authorities were constantly increasing the presence of police forces in the Serb-populated northern part of Kosovo, dangerously escalating the situation.
Meanwhile, the head of Serbia's office for Kosovo and Metohija Petar Petkovic said that Belgrade would consider returning up to 1,000 troops of its security forces to Kosovo and Metohija under the United Nations Security Council Resolution 1244 because of Pristina's controversial moves.