MILAN (Reuters/AFP) Italian Prime Minister Silvio Berlusconi was taken to hospital with blood oozing from his lips after a young man struck him in the face in a Milan square, witnesses and police said on Sunday. The Premier, who had given a speech to thousands of flag-waving supporters, collapsed after being hit and was immediately bundled into a car and taken to hospital for treatment for bruising, a member of his staff said. The Premier will stay in hospital under observation for 24 hours, ANSA news agency reported. What theyve done to Berlusconi is an act of terrorism, Umberto Bossi, head of the far-right Northern League and a close Berlusconi ally, told the Ansa news agency. Police initially said a young man had punched Berlusconi in the face, but later said the man might have hurled an object at the Premier from close range. Local news agencies said the man had been detained. Italian police have arrested a man in connection with the attack, who has been transferred to their local headquarters, the agency reported. At the beginning of the meeting Berlusconi was heckled and whistled by about 10 members of the audience. Helped by the sound system at the venue, he drowned them out, and a little later police had to intervene following scuffles between the hecklers and security staff. Berlusconi, who has come under increasing pressure in recent weeks, on Friday dismissed accusations of mafia ties made by a turncoat criminal at an Italian court earlier this month as a farce. And he said he would not bow to pressure to go to the polls early. He began his third stint as prime minister in May 2008. But a series of allegations about his private life earlier this year, which led to his wife filing for divorce, and his penchant for making controversial public statements have added to the political pressure against him.