A four-year-old boy was among the victims of an apparent mafia execution along with his mother and her partner. Two other children were left shocked but unhurt in the assault in southern Italy.

Domenico Petruzzelli was sitting in the lap of his mother's companion, Cosimo Orlando, 43, when their car was attacked by gunmen in Italy's southern Apulia region.

Police believe a hit squad in another vehicle cut up the victims' car outside the village of Palagiano, Taranto, and opened fire.

At least 15 shots were fired, killing Orlando, the child and his mother, Carla Maria Fornari, 30, who was driving.

Another two children aged six and seven, who were in the rear of the vehicle, survived.

Italy's interior minister Angelino Alfano ordered 60 extra police officers into the area.

Investigators believe Orlando, who was serving a custodial sentence allowing part-time work outside prison over a 2000 drugs-related double murder, was the target.

Police said he had recently gone back to work for local mafia bosses.

Domenico Petruzzelli was named after his father - Fornari's late husband - a mobster jailed for drug trafficking who was shot dead in a similar ambush in 2011.

Petruzzelli senior and one of his gang were killed in a hail of bullets as they were travelling by car in the Palagiano area.