ROME, Aug 10: Security in Italy's art cities, including Venice, Florence and Rome, will be tightened over the coming holiday weekend after a stream of threats from militants, officials said on Tuesday.

The Italian interior ministry sent a letter to security chiefs around the country on Monday urging them to be on maximum alert for the Assumption holiday on Sunday - the deadline set by militants for Italy to pull its forces out of Iraq or face attacks.

"This particular historic moment has imposed the need for preventive measures even in Florence, a city of art," the police headquarters in the Tuscan capital said in a statement.

"We have decided to intensify security at the main monuments and the most-frequented piazzas," it said - steps that are being matched in historic cities across Italy. A militant group claiming links to Al Qaeda sent a statement to a London-based newspaper on August 1 giving Italy 15 days to withdraw its 2,700 troops from Iraq - the third-largest foreign force there.

"Our cells in Rome and in all other Italian cities are prepared and ready to carry out their mission after the end of the truce on the 15th of this month," the group Abu Hafs al-Masri Brigades said in a later statement.

"You won't feel safe in your homes." On Tuesday, the same group claimed responsibility for bomb attacks that rocked two hotels and a gas depot in Istanbul and reiterated its threats against Italy.

"Those living in Europe, in Istanbul and Rome, and other countries which follow the despicable American policies, we will not let them be at peace as long as the people of Iraq and Palestine do not enjoy safety," it said in a statement.

An unknown Kurdish group said it carried out the Istanbul bomb attacks in retaliation for recent Turkish army operations against Kurdish guerrillas in eastern Turkey.

PROTECTING SENSITIVE SITES: The interior ministry has called the string of threats against Italy a "vast media campaign" by the militants but said it was maintaining the high security alertfirst set on July 21 and has called for extra measures this weekend.

The ministry has singled out more than 13,000 sensitive sites since 9/11 on the United States and deployed some 4,000 soldiers to help protect them. Efforts were stepped up after the March 11 train attacks in Madrid.

Instead of taking a break as millions of Italians do every year for the cherished mid-August holiday, police, troops and intelligence agents will step up their activities on Saturday and Sunday.

Security precautions have already been taken at the Vatican city state in the heart of Rome, where 24-hour metal detectors and a heavy police presence have created long queues at St. Peter's Basilica and the Vatican Museums.

Pope John Paul himself will be in France for the holiday, visiting the pilgrimage shrine of Lourdes. Tourist hot spots such as St. Mark's Square in Venice and Rome's Colosseum will be under close surveillance, along with strategic sites like airports, railway stations and power plants.

Security experts say Italian interests abroad, especially those in Iraq, could be more vulnerable targets. "Foreign sites are more approachable. Some lost embassy somewhere or a cruise ship could be easier to attack," said Alessandro Politi, an independent Italian defence analyst.

Nineteen Italians were killed in Iraq last year when a suicide bomber attacked a paramilitary police base in the southern city of Nassiriya. -Reuters