Leftist politicians have pinned blame for a racist shooting spree in central Italy on the far-right League party that looks set to make major gains in a March 4 national election.
Six African migrants were shot and wounded on Saturday in the city of Macerata by an Italian man named as Luca Traini, who last year stood as a League candidate in a local ballot, but failed to win any votes.
Police said Traini, who has a neo-Nazi symbol tattooed above his eyebrow, admitted to carrying out the drive-by shootings and had shown no remorse.
League leader Matteo Salvini, who has forged an electoral pact with former prime minister Silvio Berlusconi, distanced himself from the attack, but said the violence was the direct result of mass immigration into Italy in recent years.
"If anyone is to blame, it is the government which has allowed hundreds of thousands of illegal migrants to come here without any limits," Salvini told La Stampa newspaper on Sunday.
Leftist politicians accused Salvini of stirring dangerous sentiment in a country that struggles to get to grips with the legacy of fascist dictator Benito Mussolini, who ruled Italy from 1922 to 1943.
Seeking the moral high ground, the ruling centre-left Democratic Party (PD) called for calm. "It would be easy to stir controversy against those who fuel hatred against us every day, but it would be a mistake," said PD leader Matteo Renzi.
Opinion polls say the PD will lose next month's parliamentary election, with Berlusconi's centre-right bloc set to win the most seats, lifted in part by rising support for the League though short of an absolute majority.
After taking charge of the League in 2013, Salvini shunted the party to the far right, adopting an uncompromising anti-immigration stance and allying himself with the National Front in France and the anti-Islam Freedom Party in the Netherlands.
His strategy appears to be paying off: polls suggest the League will win up to 14 per cent of the vote against 4.1 per cent at the 2013 national election, challenging Berlusconi's Forza Italia party for supremacy in their centre-right bloc.
Pollsters say Salvini's calls for mass deportations resonate in a country that has taken in more than 600,000 mainly African migrants over the past four years.
Traini's attack came just days after a Nigerian migrant was arrested in connection with the death of an 18-year-old Italian woman, whose dismembered body was discovered stuffed into two suitcases near Macerata.