Thousands in city of Nis stood in silence for 15 minutes on Saturday, honoring railway disaster victims in a protest challenging the Serbian president's grip on power.
Thousands of students descended upon the Serbian city of Kragujevac on Saturday in the largest protest yet against the government over a deadly railway disaster in November.
Serbia wound up a rescue operation and opened an investigation on Saturday into a roof collapse that killed 14 and injured three at a railway station in the northern city of Novi Sad.
NATO official warned on Saturday that ethnic tension in north Kosovo could trigger a repeat of violence seen in the area last year, when four people died in a gun battle and NATO officials were hurt.
Serbia's government ministers on Friday agreed to reintroduce compulsory military service which was abolished 14 years ago as a step to improve the country's defence, said President Aleksandar Vucic.
The wrecks of German warship sunk in the River Danube during World War II emerged near Serbia's river port town of Prahovo, as the river's water level dropped due to drought in July and August.