Italian Prime Minister Silvio Berlusconi was taken to hospital after being punched in the face by a man holding a small statue in his hand at a rally in Milan.
The 73-year-old was left with a bloodied face after the attack, which took place outside the Piazza del Duomo.
The 42-year-old man accused of attacking Berlusconi as he signed autographs was immediately taken into custody.
Assault: Silvio Berlusconi appeared shaken as he was rushed to hospital with cuts to his face
Berlusconi was hustled into the back of a car, but he immediately got out, apparently in an effort to show he was not badly injured.
After looking out into the crowd, the premier, without saying a word, was pulled back into the vehicle.
The attack occurred after Berlusconi had just finished delivering a long, vigorous speech at the rally to a crowd of applauding supporters from his Freedom People party at about 6:30pm.
Mr Berlusconi was signing autographs when he was attacked by a man, said to be in his 30s or early 40s
They said the attacker was wielding a miniature statue of Milan's Duomo, the city's gargoyled cathedral and symbol, but couldn't say what the souvenir was made of.
Berlusconi's spokesman, speaking by telephone from the emergency room from San Raffaele hospital where the premier was taken, told Sky TG24 TV that doctors had decided to keep the premier in the hospital overnight for observation.
'We'll see what the doctors say tomorrow morning,' spokesman Paolo Bonauiti told Sky.
The exams of his jaw area included a CT scan, Bonaiuti said.
Police identified the man they were questioning as Massimo Tartaglia, 42. They said Tartaglia didn't have any criminal record.
The attack occurred at a difficult political time for Berlusconi, who has been plagued by scandals.
Last week tens of thousands of Italians fed up with the premier marched peacefully through Rome to demand his resignation.
The demonstrators expressed dismay over what they see as the businessman's conflict of interests, citing repeated government-backed laws they contend were tailored to help shield Berlusconi from prosecution in cases involving his media, real estate and sports empire. Berlusconi claims the laws benefit all citizens.
Other critics cite Berlusconi's sex scandals.
Berlusconi's wife is divorcing him after complaining about his infatuation with young women.
A southern Italian businessman has told investigators he procured some 30 attractive young women for parties and dinners at the premier's Rome residence and Sardinian villa.
Among the guests was a high-end prostitute who claimed she slept with Berlusconi. The premier has denied ever paying for sex.
Berlusconi has steadfastly denied any wrongdoing and blames his judicial woes on prosecutors he claims sympathize with the opposition left.
Several of the cases either ended in acquittal or were dropped when limitation statutes expired. Others are pending.
