A man broke into his ex-wife's house in São Paulo where she was celebrating the new year with family and shot her dead. He was carrying "several firearms" said Corporal Marta Aurelia on 1 January. It's believed that at least 30 shots were fired.

The incident took place in the south-eastern city of Campinas, São Paulo State, Brazil. Other fatalities included the estranged couple's 8-year-old son, as well as his ex-wife's relatives.

In total, 13 people were killed, including the gunman, who committed suicide by shooting himself in the head.

Four others were wounded and taken to Unicamp and Ouro Verde hospitals.

According to reports, Sidnei Ramis de Araujo, 46-year-old laboratory technician jumped over the wall at the house where a New Year's Eve party was taking place and started shooting, according to Globo News.

An eyewitness told police that he saw his uncle lying on the ground. Fear for his life, the man ran and locked himself in a bathroom. The witness heard the gunman say he was going to kill his ex-wife because she had custody of their son.

The incident was reported as a homicide followed by suicide, according to police. At the scene of the crime, a 9mm calibre pistol, ammunition, a knife and explosives were found in the gunman's possession.

Military police say that the gunman was suffering from mental health problems due to the break-up of his marriage.

Financial analyst Cristiano Machado and his family rescued one of the victims when they knocked on his door for help. "We heard the noise of shooting, we were in doubt if they were shots or fireworks, which was at a quarter to midnight."

Violence against women is at epidemic proportions in Brazil, where around 15 women are killed every day, according to authorities, often in domestic violence disputes.