Interior Minister Luciana Lamorgese’s office said it will send extra police forces to the southern city, home to the Sacra Corona Unita (SCU) mafia.

The ministry also confirmed it will open a special office of organised crime investigators.

Thursday’s attack targeted an aged care residence run by a cooperative managed in part by Christian Vigilante, a witness in a major trial against alleged gangsters, according to local police reports.

No one was injured in the attack.

The explosion followed a bombing two weeks ago that destroyed Vigilante’s car and damaged six other vehicles.

The first attempt on Vigilante’s life provoked 20,000 people to march through the streets of Foggia in a protest organised by the anti-mafia group Libera.

The bombings follow the year’s first murder in the area, when a 50-year-old man was shot in his car by assailants on a scooter.

Lamorgese said she was “utterly determined” to bring down the mob, and said she was counting on “the mobilisation of all civil society … to respond to criminal attacks without fear”.

Italian Prime Minister Giuseppe Conte backed Lamorgese’s cause.

“The state, and citizens of Foggia, will not be cowed,” Italian Conte wrote on Twitter following the bomb.

“Investigators are already at work, and we will not give respite to those who think they can use violence to banish legality, freedom and justice. We will win this battle together.”

The SCU is widely known as Italy’s “fourth mafia”, after the Cosa Nostra in Sicily, the ’Ndrangheta in Calabria and the Camorra in Naples.