Rome officials were busy working on security measures on Tuesday as the capital prepared for a visit by US President George W. Bush and braced itself for a major demo by anti-war protesters.
Bush will arrive in Rome on Friday evening from Poland, which he will briefly visit after taking part in the Group of Eight summit in Germany.
His Rome trip, which ends on Sunday morning, will include talks with centre-left Premier Romano Prodi and President Giorgio Napolitano and a visit to the Vatican to meet Pope Benedict XVI.
Italian pacifists and other demonstrators are planning a massive anti-Bush protest which is expected to draw thousands of supporters from across the country.
Some 8,000 extra police will be on duty amid fears that violent militants could infiltrate the demo.
Security officials are particularly concerned that militants known as the 'black block' could move down to Rome after taking part in anti-G8 protests in Germany.
The black block were blamed for the violence which marred a demonstration in the German port city of Rostock on Saturday, close to the resort of Heiligendamm where G8 leaders will meet from Wednesday to Friday.
More than 1,000 people were injured in clashes between police and protesters in what was the worst street violence seen in Germany for years.
Security will be stepped up along Italy's frontiers and ports in a bid to prevent potentially violent activists entering the country from Germany, Austria, Spain, Greece and France.
But organisers of the Rome anti-Bush protest insist the event will be peaceful and have accused security officials of trying to discredit their march by creating unnecessary alarm.
"This is a mass pacifist rally. It won't be another Rostock," the organisers told journalists on Tuesday.
The demo is supported by some 200 anti-war organisations ranging from trade unions and student groups to activists angry at the expansion of a US military base in the northern city of Vicenza.
The march will kick off at 15:00 on Saturday afternoon and wind its way through the city centre to a famed square, Piazza Navona.
Meanwhile, the main concern for security officials is a planned trip by Bush on Saturday to the picturesque neighbourhood of Trastevere in the heart of Rome where he intends to visit one of the city's oldest churches, Santa Maria in Trastevere.
The US president is also slated to visit the nearby headquarters of Sant'Egidio, a Catholic organisation known for its mediation efforts in international conflicts.
But Trastevere is a maze of small streets, squares and alleys, making security particularly difficult.
Police are considering setting up a temporary, 10-metre-long tunnel near the Trastevere church which will allow the Bush delegation to travel through the area in greater safety.
Access to the neighbourhood will be blocked on Saturday and rubbish bins and manholes sealed.
Security has already been tightened at Rome's Fiumicino airport, where Bush will be touching down on Friday aboard the presidential plane Air Force One.
Helicopter gunships will be deployed during Bush's stay, when air traffic over the city will be limited.
Bush will be accompanied by his wife, First Lady Laura Bush, who will join her husband on his trips to the Vatican and Santa Maria in Trastevere.
At the end of his official appointments on Saturday, Bush will meet up with opposition chief and former premier Silvio Berlusconi.
Berlusconi was a close ally of the president during his five years as premier (2001-2006) and was described as an "old friend" by a White House spokesman on Monday.
VISIT COMES AFTER TENSIONS BETWEEN ALLIES.
Bush's trip comes after tensions between Rome and Washington over foreign policy and other issues.
America was among allies who criticised Italy over its handling of a recent hostage crisis in Afghanistan which ended after five Taliban prisoners were released in exchange for the life of an Italian journalist.
Another source of friction is the case of Nicola Calipari, an Italian secret agent killed in March 2005 in a controversial 'friendly fire' roadblock incident in Iraq.
A US soldier has just gone on trial in Italy in absentia accused of murdering Calipari.
The Italian courts are also about to open a trial against 26 CIA operatives accused of kidnapping a Muslim cleric in Milan in February 2003.
The trial would be the first judicial examination of America's controversial rendition policy, the abduction of terrorism suspects in one country in order to have them interrogated in another.
Plans to expand the American military base in Vicenza have also sparked tensions, drawing fierce protests from city residents and leftist elements in Prodi's coalition.
The incidents have however done nothing to dent the firm ties between Italy and the US, officials stress.
