Serbia held a national day of mourning on Wednesday after a war veteran rampaged through a tiny village near Belgrade, shooting dead 13 relatives and neighbors, including his son, his mother and a 2-year-old.

Flags stood at half-staff throughout the country, and newspapers blacked out their front pages to commemorate Serbia's worst such massacre in two decades.

"The worst crime in the history of Serbia," read the headline on the front page of the Belgrade daily Nase Novine.

Radmilo Bogdanovic, brother of Ljubisa Bogdanovic, cries in village of Velika Ivanca, Serbia, on Tuesday. Bogdanovic gunned down 13 people, including a baby, in a house-to-house rampage. wsday before trying to kill himself and his wife, police and hospital officials said. Darko Vojinovic / AP

"The war veteran massacred half a village as it slept," added the tabloid, above photos of all 13 victims.

Most papers carried pictures of shocked and weeping relatives and neighbors in the village of Velika Ivanca, about 50 km south of Belgrade.

The gunman, identified as 60-year-old Ljubisa Bogdanovic, went house-to-house at 5 am local time on Tuesday, methodically shooting his victims in five houses on a hill on the outskirts of the village, police said.

The houses are only about 10 meters from each other.

He killed six men, six women and the child, a 2-year-old boy, according to the victims' neighbors. He then shot himself in the head and attempted to kill his wife, Javorka.

He is "unconscious and in critical condition", said Zorica Markovic, the spokeswoman for Belgrade's main hospital, while Javorka Bogdanovic's life is not in danger, medical authorities said.

The killing spree has sparked a new debate on gun control in the Balkan country, with Prime Minister Ivica Dacic saying society needed to "pay more attention to prevent such crimes".

Serbian police chief Milorad Veljovic said a new law, prepared after a similar incident in 2007, will be sent to Parliament "in the coming days".

"The draft law foresees a medical examination every three to five years for all those who have a license for a gun or ammunition," Veljovic told national broadcaster RTS.

According to 2007 research at the Geneva-based Graduate Institute of International and Development Studies, Serbia had the fifth-largest civilian firearms arsenal out of 178 countries, with an average of 37.8 guns per 100 inhabitants.

It was a "monstrous" crime, the police chief told reporters on the scene.

Ljubisa Bogdanovic's motive for the bloodbath remained unclear, and his wife was battling to come to terms with the 60-year-old's sudden spree of violence.

Speaking to police from her hospital bed, Javorka Bogdanovic said her husband had a "bad temper" but she had no idea what could have driven him to the massacre, the Vecernje Novosti daily reported in its online edition.

"He had a bad temper, but I did not dream of this. We were all like a big family," she said.

Locals said his father had committed suicide when he was a child while some of his family members had undergone psychiatric treatment in the past.

Agence France-Presse