ROME, Aug. 1 (Xinhuanet) -- The head of the Italian police's anti-terrorism department, Carlo De Stefano, admitted on Monday that the risk of a terror attack in Italy was real.

    "Unfortunately, the possibility exists," De Stefano said at a press conference called to outline the situation after the arrest of one of the July 21 London bombers in Rome.

    "Security authorities have done everything possible to prevent such acts," he stressed.

    A week ago, an Islamist terror group repeated an ultimatum for Italy to pull its troops out of Iraq by mid-August or face a terrorist campaign at home.

    The Abu Hafa al-Masri group said it would "turn Rome into a graveyard."

    "After London it's Rome's turn," said the message on an unidentified Internet site spotted by Israeli intelligence.

    Abu Hafa al-Masri on July 9 claimed responsibility for the terrorist bomb attacks which killed 52 in London and the bomb attacks which killed 190 in Madrid in March of last year.

    Meanwhile, Rome Prefect Achille Serra denied on Monday press reports that authorities had prepared to advise people on how to defend themselves from terrorist attacks.

    "The only advise we can give people is to remain alert, report anything suspicious to police, but without turning normal life upside down, naturally," he said. Enditem