Two Italian police officers and a passerby have been wounded outside the prime minister's office in Rome in a shooting incident that took place as Prime Minister Enrico Letta's new government was being sworn in just a kilometer away.
One of the officers was said to be in serious condition.
It was not immediately clear whether the April 28 shooting was related to the ceremony.
"An initial examination of the incident suggests that this can be considered as an isolated act," Reuters quoted newly installed Interior Minister Angelino Alfano as saying. He added that further checks were being carried out.
Alfano said there was no cause for concern about the overall security situation in the country, but he added that authorities had stepped up protective measures at potential targets.
An unemployed man in his 40s was arrested following the shooting, Reuters reported.
The swearing-in comes after two months of political stalemate in the eurozone's third-largest economy.
Prime Minister Enrico Letta's cabinet is expected to face its first vote of confidence in parliament early next week.
Letta, the 46-year-old leader of the center-left Democratic Party, was the first to take the oath of office at the ceremony led by President Giorgio Napolitano.
His government is a coalition between Italy's main center-left and center-right parties, including former Prime Minister Silvio Berlusconi's center-right People of Freedom (PDL) party.
Berlusconi himself will not be a minister but Angelino Alfano, the PDL secretary, will serve as deputy prime minister and interior minister.
Berlusconi, who has served three terms as prime minister, resigned in 2011 as Italy slipped deeper into a financial crisis.
He is still contesting tax fraud charges and charges of having had sex with an underage prostitute, but he has recently regained popularity.
The government also includes Fabrizio Saccomanni, the director general of the Bank of Italy, who will serve as economy minister.
Former European Commissioner Emma Bonino will be the foreign minister.
The Democratic Party, Berlusconi's PDL and the protest Five Star Movement of comedian Beppe Grillo each obtained around one-quarter of the national vote in the inconclusive February election.
The center-left beat Berlusconi's conservatives but failed to win a majority. Grillo has refused to join a coalition with the two main parties.
Napolitano, the 87-year-old president who is serving an unprecedented second term, has threatened to resign if the government fails to enact reforms.
Based on reporting by Reuters, AP, and dpa