A man shot dead five people, including his wife, and injured another 20 in a cafe in northern Serbia early on Saturday, police said, with jealousy the suspected motive.
The man "entered the cafe and opened fire with an automatic rifle, killing his wife and another woman, then he continued to shoot at other citizens in the cafe," a police statement said.
Interior Minister Nebojsa Stefanovic visited the scene and was quoted by N1 television channel as saying that the weapon was illegal and jealousy was believed to be the motive.
It is the third mass shooting in recent years in Serbia, which has tried to shrink the number of illegal weapons in circulation since the 1990s Balkan wars.
The latest incident happened at about 1:40 am (2340 GMT Friday) in the town of Zitiste, around 80 kilometres (50 miles) north of Belgrade.
Police arrested the alleged shooter, born in 1978 and named only by his initials Z.S., and opened a probe into the killings.
Stefanovic said the attacker tried to flee the scene, but police stopped and arrested him.
"We are all shocked that something like this could happen, since this was a very quiet man who had no police record," he said according to the state-run Tanjug news agency.
Serbia's worst shooting spree
N1 channel reported that the attacker argued with his wife in the cafe, left the building and returned with a Kalashnikov-type rifle with which he opened fire.
Two people were killed instantly, while three died after being taken to hospital in the nearby city of Zrenjanin, the channel's report said.
The others wounded, some of them severely, were taken to various Serbian hospitals but were not in critical condition, reports said.
Illegal gun ownership is widespread in Serbia and the rest of the former Yugoslavia.
Police have previously said there could be several hundred thousand unregistered weapons in the country, including guns and grenades, remaining from the 1990s Balkan wars.
The shooting spree came a day after the interior ministry launched a new drive to encourage owners of illegal weapons to hand them in to their local police stations.
Such people "will not be held accountable for unauthorised buying and holding of weapons," the police announcement said Friday.
Saturday's mass shooting is not the first in recent years for Serbia.
Last year a 55-year-old man went on a shooting spree in a northern Serbian town in an apparent drunken rage over his son's wedding, killing six people including the bride and her parents.
In 2013 a 60-year-old Serbian war veteran shot dead 13 people in the country's worst massacre in two decades as he rampaged through his tiny village about 50 kilometres south of Belgrade.
The dead included his son and his mother as he went house-to-house, mainly shooting people in the dead as they slept peacefully.
The gunman later died from a self-inflicted gun wound.
