Veteran injured in police battle as tension rises in US

In Atlanta, police arrested 53 protesters who were camping in the city's park downtown

An Iraq veteran was still in critical condition yesterday after being injured when an anti-Wall Street demonstration in Oakland degenerated into a battle with police using tear gas, the most vivid sign yet that some US city governments are starting to lose patience with the protest movement.

It remains unclear who fired the projectile that struck Scott Olsen, fracturing his skull, though protesters said a teargas canister was responsible. Whatever the truth, the incident could be a turning-point in the thus far peaceful movement which has spread to scores of US cities since the first Occupy Wall Street banners appeared in New York's Zuccotti Park six weeks ago. On Wednesday, 10 people were arrested in lower Manhattan, after hundreds had marched past City Hall in support of Mr Olsen.

In Atlanta, police arrested 53 people camping in the city's downtown Woodruff Park. They too were protesting against the growing wealth disparity between the rich and everyone else, the "99 per cent" as the demonstrators describe themselves. Atlanta's Mayor, Kasim Reed, had been supportive of the protesters, twice issuing executive orders allowing them to remain as he tried to walk a fine line between safeguarding free speech and the right of free assembly and maintaining public order. But the longer the camp-out went on, the greater the risks posed by crime and unsanitary conditions. Mr Reed too began to lose patience. "What I've seen here is not consistent with any civil rights protests I've seen in Atlanta," he told The New York Times.

In Baltimore, where dozens of "Occupy Baltimore" protesters have set up camp in the heart of the city, Mayor Stephanie Rawlings-Blake said she had "absolutely no interest in a violent exchange". But, she insisted, demonstrators should understand they are camping in a city park and that was not its intended use. The Occupy Wall Street movement has no leaders and no specific platform. But polls show its broad goals, of a fairer society and a reduction of the influence of money on politics, are generally supported by Americans.

Many Democratic strategists have urged President Obama to embrace the movement and make its demands his own. But despite his flagging approval ratings, he has gone no further than expressions of sympathy with its broad aims.