Cops defuse bomb ahead of political rally in Rome

“If it had exploded it would have not only caused serious damage to the facades of the surrounding buildings, but would have caused the deaths of passers-by in this very busy neighbourhood,” an investigator said.

Massimo D’Alema, the head of the Democratic Party of the Left (PDS), the biggest party in the Government coalition, and former top anti-mafia judge Antonio Di Pietro walked past the scene shortly afterward en route to an election rally nearby.

They were on their way to support Rome Mayor Francesco Rutelli ahead of Sunday’s first-round of municipal elections.

Italy’s Secretary of State for Interior Adriana Vigneri described the incident as “very serious” because of the timing.

But Rome police chief Rino Monaco said: “It is too soon to make interpretations. Nobody has claimed the attack and the target may have been the courts.”

The Mayor said: “I hope there was nothing premeditated in this to sow panic and terror in the city.”

Some 12 million people will vote in the first-round of municipal elections in towns and cities across the country including Rome, Naples, Palerma and Venice.

The elections are widely predicted to result in victories for the Centre-Left Government, and there has been little controversy in the campaign so far.

Investigators suspect anarchist militants of planting the bomb, which caused no casualty.