Two Italian paramilitary police officers have been shot and wounded outside the Rome office of new premier Enrico Letta as he was being sworn in nearby presidential palace.
The gunman and a female passerby were also injured in Sunday's incident outside Palazzo Chigi, the building the hosts the premier's office, Italy's ANSA news agency said.
A police official said that one of the wounded police officers had been shot in the neck and was in a serious condition after the shooting on Sunday.
The attacker, named by Italian media as businessman Luigi Preiti, 49, was tackled to the ground by police as a crowd, which was waiting for Letta to arrive, fled the scene.
Police reportedly arrested a well-dressed man at the scene of the shooting in Rome, where a crowd was waiting for Letta to arrive.
'Tragic criminal gesture'
Angelino Alfano, Italy's interior minister, said the shooting was a "tragic criminal gesture by an unemployed man.''
Reports of the shooting prompted police to order an evacuation of the area around the nearby presidential palace, where the new cabinet was being sworn in.
The incident took place as Leftist moderate Enrico Letta was formally sworn in as Italy's prime minister and head of a new coalition cabinet at a ceremony lead by President Giorgio Napolitano.
The cabinet's 21 ministerial posts have gone to a mix of experts and institutional figures from across the political spectrum to form a "grand coalition" which brings to an end a damaging political deadlock left by inconclusive elections.
Letta's ministers stepped forward one by one to swear allegiance to the republic before President Giorgio Napolitano, who personally picked Letta as prime minister and had a central sole in the choice of his cabinet team.
The ceremony ended two months of bitter post-election deadlock in the recession-hit EU country.
Letta, 46, is expected to unveil his programme in a parliamentary session on Monday.The government will be put to a confidence vote in parliament on Tuesday.
The political deadlock had thwarted efforts to end the worst recession in Italy in 20 years, and Letta has said he wants to move quickly to tackle unemployment, which has hit 11.6 percent, and boost growth.
The leftist leader wants to move away from the austerity imposed by his technocrat predecessor Mario Monti to protect Italy from the eurozone debt crisis. That promise will be followed closely by investors concerned about the country's two-trillion-euro debt.
An official forecast predicted Italy's to rise to 130.4 percent of gross domestic product this year.
Letta said as he unveiled his new cabinet on Saturday that he was proud to have included younger ministers - the average age is 53 - and more women to help renew the country's tired political scene and rebuild confidence in the discredited political class.
Commentators said the exclusion of any of Italy's big political names was an attempt to avoid infighting within the coalition and acknowledge a growing call from the electorate for change.
Stefano Folli, political expert for Il Sole 24 Ore, noted "many women, many new faces, and the exclusion of almost all of those who represented the historical dispute" between left and right.
Letta named as his deputy Angelino Alfano, protege of former premier Silvio Berlusconi and secretary of the centre-right People of Freedom party (PDL).
While the appointment appeared to be aimed at appeasing the right, it angered critics of the scandal-tainted billionaire tycoon, who they claimed would have a grasp on the reins of power.
The popularity of Berlusconi, who is on trial for paying for sex with a 17-year-old prostitute, has risen, as he fought to have his right-hand man in pole position.
Alfano will also become interior minister.