Police in Serbia say a man opened fire with an automatic weapon in a cafe early Saturday, killing his wife and four other people.
At least 22 other people were wounded with seven in a serious condition, the director of a nearby hospital said.
Police arrested the suspect, a man in his late 30s identified by the initials ZS, immediately after the shooting and opened an investigation into the killing.
Serbian Interior Minister Nebojsa Stefanovic told Belgrade's B92 TV that the man killed his estranged wife and another woman, before firing indiscriminately at others in the cafe with an illegally owned assault rifle.
Stefanovic said jealousy could be a motive, as the suspect was known to be a quiet man with no criminal record.
The incident happened during a local festival in the village of Zitiste, around 80 kilometers north of the capital, Belgrade.
It was the third mass shooting in recent years in Serbia, which is trying to reduce hundreds of thousands of weapons in circulation since the 1990s Balkan wars.
Three years ago, 13 people died in a shooting spree in a village near Belgrade, and last year six people were killed in a dispute over a wedding in northern Serbia.
Saturday’s mass shooting came one day after the interior ministry offered an amnesty to encourage owners of illegal weapons to surrender or register them.