A migrant was killed and another injured on Monday in a street clash in central Belgrade, Serbia's interior ministry said.
Police "arrested five migrants suspected of participating in the clash and found knives on them," a ministry statement said. The injured person was taken to hospital.
The statement did not give further details but local media reported that the man who died was from Afghanistan.
The incident occurred on a central street near a park where hundreds of migrants gather each day to rest on their journey through the Balkans towards western Europe.
Some 6,300 migrants are currently stuck in Serbia, mostly in reception centres around the country of seven million people, according to the UN refugee agency.
About 1,000 migrants are sleeping rough in the capital, the agency says.
Serbia lies on the so-called Balkan route taken by hundreds of thousands of migrants from the Middle East, Asia and Africa since 2015.
Although the route was effectively shut down in March, migrants have continued to cross the region in smaller numbers, often with the help of traffickers.
According to Serbian authorities, more than 102,000 migrants have been registered in the country since the beginning of this year.