At least one student said they knew the shooter personally, and that it was a pre-planned attack.
Serbia inherited most of the former Yugoslavia's military industrial facilities and has made billions of dollars from weapons exports.
"If this document is accurate, it either shows Vucic's duplicity vis a vis Russia or he's under enormous pressure from Washington to deliver weapons to Ukraine," said Janusz Bugajski
Serbian President Aleksandar Vucic and Kosovo Prime Minister Albin Kurti agreed to implement normalization steps at a meeting with EU officials.
Kosovo Prime Minister Albin Kurti and Serbian President Aleksandar Vucic held separate meetings with European Union foreign policy chief Josep Borrell before a three-way session in North Macedonia.
Serbian nationalists, who want closer ties with Russia, criticize President Aleksandar Vucic for his role in talks over a Western-backed deal with Kosovo.