ROME, March 23: A U.S. security alert advising Americans of possible pre-election violence in Italy set off a storm of controversy on Thursday with the centre-left opposition saying it created a “climate of fear”.

The United States cited the possible threat of an Al Qaeda attack ahead of the April 9-10 ballot and also pointed to the risk of domestic rallies turning violent after opponents of the conservative prime minister rioted in Milan this month. An nail-bomb injured police and at least 40 people were arrested.

Centre-left leader Romano Prodi, who is accused by his political foes of being weak on terrorism and tolerant of leftist radical violence, called the US ambassador to Italy to demand an explanation.

“The US alert surprised me. It creates a climate of fear and is not needed,” said Prodi, who is leading in opinion polls.

“He (the US ambassador) told me that it is routine, but I was really taken aback.”

Berlusconi pounced on Prodi, saying he had no right to tell the US how to advise its citizens.

He also renewed accusations that Prodi’s centre left was to blame for the Milan violence and would endanger Italy if elected since it included anti-globalisation leaders in his coalition.

“(Prodi’s) outburst is meant to cover up the reality of things — that the left is the home of people who practice violence,” Berlusconi said.

Berlusconi has accused his opponents of sending gangs of thugs to disrupt his rallies and said Italy faced a “democratic emergency”.

AL QAEDA THREAT: A US embassy spokesman in Rome said the State Department had sent out about 70 similar announcements in the past year, including one during the riots in Paris in 2005.