OAKLAND (CBS SF) — The Iraq War veteran who was critically injured in a clash between police and Occupy Oakland protesters earlier this week was upgraded to fair condition on Thursday, doctors said.

Scott Olsen, who served two tours of duty in Iraq as a U.S. Marine, was transferred from the emergency room to the intensive care unit at Oakland’s Highland Hospital. Doctors said he suffered a fractured skull.

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Olsen, 24, was apparently injured during a march with other protesters toward Oakland City Hall on Tuesday night. The demonstrators were trying to re-establish a presence in the area of a disbanded protesters’ camp when they were met by police officers.

It’s not known exactly what type of object struck Olsen or who might have thrown it during the clash, but the group Iraq Veterans Against the War claimed that police officers were responsible for his injury.

Oakland Police Chief Howard Jordan said both police and prosecutors were looking into whether officers used excessive force during the clash. He added that six to seven injuries were reported during the violent demonstration — including Olsen’s head injury.

“It’s unfortunate it happened. I wish that it didn’t happen. Our goal, obviously, isn’t to cause injury to anyone,” Jordan said.

But Olsen’s uncle George Nygaard, speaking on behalf of his family, told reporters that they were appalled by the police officers’ action.

“He’s somebody who went over there and fought for our freedom comes back and is viciously attacked for exercising his First Amendment rights,” said Nygaard, himself a Vietnam veteran.

Olsen was awarded seven medals during his four years of service in the Marine Corps; he was discharged at the rank of lance corporal in November 2009.

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In more recent times, Olsen’s current roommate said he felt so strongly about economic inequality that he wanted to do something to change it – that’s why he participated in the anti-Wall Street movement.

Keith Shannon stold the Associated Press that Olsen joined the protests as he worked his day job as a network engineer at the security software company OPSWAT in Daly City. He left their hillside apartment, overlooking San Francisco Bay, at night to sleep alongside Occupy movement protesters in both San Francisco and Oakland.

“He wasn’t active in politics before he went in the military, but he became active once he was out. The experience in the military definitely shaped him,” Shannon said.

Olsen’s co-workers described him as a humble, quiet guy who worked hard over long hours.

“Obviously it’s pretty devastating for us that he’s in the shape he’s in,” Jeff Garon, the company’s director of marketing, told the AP.

Since he was injured, Olsen’s name has become a rallying cry for protesters around the nation. On Wednesday night, demonstrators in New York City, where the movement began last month, marched in support of their counterparts in Oakland.

One movement website, OccupyWallSt.org, declared: “We are all Scott Olsen.”

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