Occupy Wall Street protesters move to Times Square
Police in New York have arrested about 70 people, as Occupy Wall Street protesters moved to Times Square.
Forty-five were detained in the square, with another 24 held for alleged trespassing at a branch of Citibank near Washington Square Park.
The protests came on a day of worldwide protests against austerity and what protesters call corporate greed.
At least 70 people were injured after a peaceful rally in the Italian capital Rome descended into street battles.
Prime Minister Silvio Berlusconi called the violence a "worrying signal" and said the perpetrators "must be found and punished".
Rome Mayor Gianni Alemanno blamed the violence on "a few thousand thugs from all over Italy, and possibly from all over Europe, who infiltrated the demonstration".
Series of rallies
Organisers of the New York march from Zuccotti Park in Lower Manhattan to Times Square said about 5,000 people took part.
Protesters chanted: "We got sold out, banks got bailed out" and "All day, all week, occupy Wall Street."
One woman was injured when she fell as police on horseback tried to clear protesters from Times Square.
Staff at Citibank near Washington Square Park called police because "very disruptive" protesters "refused to leave after being repeatedly asked," the bank said.
"The police asked the branch staff to close the branch until the protesters could be removed."
There were also protests in a number of other US cities, including 5,000 people who rallied outside City Hall in Los Angeles and 2,000 who marched in Pittsburgh.
The New York protests began on 17 September with a small group of activists and have swelled to include several thousand people at times, from many walks of life.
The Rome protests began when tens of thousands of people gathered under anti-austerity banners, close to the ruins of the Colosseum.
However, militants dressed in black, some of them wearing balaclavas and crash helmets, soon appeared in the crowd and began attacking property.
Cars were burnt, and cash dispensers, banks and shops were attacked, with windows smashed.
A huge rally in Madrid had a more festive atmosphere.
Tens of thousands of people filled the Puerta del Sol Square on Saturday evening, the BBC's Sarah Rainsford reports from the Spanish capital.
People of all ages, from pensioners to children, and many of the young unemployed, filled the square, where the "Indignant" movement was launched in May.
In Portugal, 20,000 marched in Lisbon and a similar number in Oporto.
In Greece, about 2,000 people rallied outside parliament in Athens and a similar number reportedly turned out in the second city, Thessaloniki.
At least 1,000 people demonstrated in London's financial district but were prevented by police from reaching the Stock Exchange, and five arrests were made.
About 500 protesters spent the night camped outside St Paul's cathedral
Protests were also held in a number of cities across Asia.