After an early council of ministers, Alfano told a press conference the accident was identified as being an isolated gesture. "The general situation of public order in the country is not a matter of concern," he said, adding that however "checks have been reinforced over the objectives at risk."

Letta and his team are expected to win a confidence vote of both chambers of parliament on Monday and start the urgent task to deal with declining economy and rising unemployment in a country plagued by recession after becoming one of the first eurozone victims of the global crisis.

Letta has pledged to cut political costs and change a voting law considered largely responsible for the inconclusive results of February's national elections. But according to political observers, the coalition will likely prove to be uneasy after the bitterness of disputes between the PD and the PdL in recent years.

The third largest force in parliament, the Five-Star Movement (M5S) whose success was a response to public anger with the scandal-hit established politicians, refused to take part in what it defined a "shady deal" between the two rival parties.

The Internet-based movement clarified its firm opposition to all forms of violence after the shooting, echoing appeals from the entire political and civil world to tone down and not stir up trouble in the current difficult times.