Italy may tighten its border controls and suspend the EU's Schengen rules during next year's Winter Olympics in Turin in an attempt to stop terrorist attacks, an Interior Ministry official said.

"We do not exclude a suspension of Schengen," Francesco Tagliente, the head of the Interior Ministry's public security office, told a news conference.

Passport-free Schengen rules apply to 15 European countries and allow travellers between them to cross borders without showing an identity card, unless they are using aircraft.

Italy, a close ally of the United States, has received numerous Internet threats purported to be from Islamic militants and Interior Minister Giuseppe Pisanu has said the Feb. 10-26 Games are at risk.

Prime Minister Silvio Berlusconi heightened concern this week when he said in a newspaper interview a suicide bomber was plotting to kill him at a soccer match.

An interior ministry official at the news conference confirmed there was a suicide bomber threat against Berlusconi.

However, Tagliente played down the risk for the Olympics and said demonstrations by local environmental or anti-globalisation protesters were a more likely problem.

"At the moment, information available does not show specific risks at sporting events," he said.

Scare stories sparked by high security at the Athens Summer Games were blamed for many of the athletes competing in half-empty stadiums and the Olympics organising committee is keen to prevent a replay of that in Italy.