Serbia's Prime Minster warned Thursday against attacks on Bosnia's Serb entity in light of the impending verdict from a U.N. war crimes court on its founder and former leader, Radovan Karadzic.

Judges at the International Criminal Tribunal for the former Yugoslavia (ICTY) mid-afternoon began delivering their long-awaited verdict on Karadzic, who founded the Republika Srpska (RS), a breakaway Bosnian territory, in 1992.

Supporters of the late Serbian strongman Slobodan Milosevic paid their respects at his grave Friday, 10 years after he died in The Hague where he was on trial for war crimes.

Known as the "Butcher of the Balkans", Milosevic fueled ethnic conflict and mass murder in the former Yugoslavia during his 13 years of iron rule, defying international sanctions and NATO bombs.

War crimes judges on Wednesday piled pressure on Serbia to arrest three suspects over alleged witness tampering in the case of an ultra-nationalist, warning Belgrade is "not cooperating" with the U.N. tribunal.

The International Criminal Tribunal for the former Yugoslavia (ICTY) in January 2015 issued arrest warrants for indicted war criminal Vojislav Seselj's defense team lawyers, Petar Jojic and Vjerica Radeta, as well as a former war-time associate Jovo Ostojic.

The Yugoslav war crimes court Wednesday ordered the provisional release of two top Serbian officials from the regime of the late Slobodan Milosevic pending their retrial for crimes committed during the 1990s Balkans wars.

Judges at the International Criminal Tribunal for the former Yugoslavia (ICTY) said they were "satisfied that, if provisionally released" Jovica Stanisic and his deputy Franko Simatovic, both 65, "will appear for trial."

Croatia has refused a request from Slovenia to take back migrants who have crossed the countries' shared border and are not fleeing war, a police spokesman told Agence France Presse Thursday.

"Slovenia asked us for the re-admission of 162 people. We did not accept that and have informed our neighbours about everything," Croatian police spokesman Domagoj Dzigumovic told AFP.

Bosnian police on Wednesday arrested five wartime officers and an ex-politician, all ethnic Serbs, suspected of involvement in the deaths of hundreds of civilians during the country's 1990s conflict.

"These people are suspected of implementing, as senior military officials... the expulsion of some 5,000 Muslim and Croat civilians from Kotor Varos," a northwestern town, the prosecutor's office said in a statement.

Serbian Prime Minister Aleksandar Vucic paid his respects Wednesday to Muslim victims of the 1995 Srebrenica massacre, four months after being chased from a ceremony in the Bosnian town by a stone-throwing mob.

Vucic, a former ultra-nationalist turned pro-European, laid a wreath of white roses at Srebrenica's memorial, in the presence of the town's Muslim mayor and Bosnian Muslim leader Bakir Izetbegovic.

Kosovo's constitutional court on Tuesday suspended the implementation of a key EU-backed agreement with Serbia, after weeks of opposition protests against the deal.

The move came a day after the U.N. cultural body UNESCO rejected Kosovo as a member, in a vote hailed as a victory by Belgrade.

When jubilant crowds stormed Belgrade's parliament 15 years ago and ousted Serbian strongman Slobodan Milosevic, few could have imagined that his allies would be in power today -- and firmly backing European integration.

Monday marks the anniversary of the overthrow of the late president, whose 13-year iron rule stoked brutal ethnic conflict and mass murder in the former Yugoslavia, resulting in international isolation and the crippling of the Serbian economy.

Croatia on Saturday announced an unprecedented spike in the arrival of migrants on a long, dangerous journey towards western Europe as the continent's worst post-World War II refugee crisis showed no sign of abating.

With many of the people fleeing war and misery flocking towards Germany, a new poll showed Chancellor Angela Merkel's popularity at home has been hit by her policy of openness.