The defense ministry in Belgrade confirmed the killing on Wednesday. Security forces were patrolling the town of Pirot a day earlier when they "heard a shot and then met six migrants, one of whom had been shot in the chest," a defense ministry statement said.

Four hunters were also found on the spot and police arrested one who was suspected of having killed the 20-year-old Afghan.

"Upon the arrival of emergency services, doctors could only establish the death of a 20-year-old male citizen of Afghanistan," the statement added.

According to the United Nations High Commission for Refugees (UNHCR), around 4,400 migrants are currently stuck in Serbia.

The so-called Balkan route was closed this year in March after more than 1 million refugees - from Syria, Iraq, Afghanistan, Eritrea, Ethiopia and other North African countries - crossed it on their way to Western Europe last year. Hundreds are still crossing from Bulgaria into Belgrade's territory, in the hope of making it to Hungary and to Europe's more prosperous nations.

Around 3,700 migrants have tried to illegally cross the Serbian border since the country began joint army and police patrols to tighten frontier controls in July.

mg/rc (AFP, AP)