Story highlights The shooting suspect is a war veteran who never seemed violent, a broadcaster reports

The man goes house to house, killing occupants; six women, six men and one child die

Murder is rare in Serbia, according to the World Health Organization

A gunman went on a shooting spree in the Serbian town of Velika Ivanca on Tuesday, killing at least 13 people, including a small child, according to Police Chief Milorad Veljovic.

The town lies roughly 25 miles south of the capital, Belgrade.

The man, in his 60s, entered five houses and shot six men, six women and one child dead.

Twelve of the victims died immediately, another died at a Belgrade hospital, Serbian news agency Tanjug reported. Two people remained hospitalized, one of them likely the suspected shooter, Tanjug reported, citing Veljovic.

Veljovic said the gunman attempted to kill his wife and take his own life, according to Tanjug.

It was not immediately clear whether the man's wife survived.

Investigators don't know what sparked the killings, Veljovic said.

Serbian broadcaster B92 described the man as a veteran of the Serbian-Croatian war in the 1990s who had lost his job a year ago. Neighbors said the man had never seemed violent, B92 reported.

Serbia has a low murder rate, nearly on par with that of Sweden, according to the World Health Organization. With 1.2 intentional homicides per 100,000 inhabitants in 2010, Serbia's murder rate was one-quarter of that of the United States.