Updated

Investigators will review hundreds of hours of video of a Los Angeles immigration rally where police wielded batons and fired rubber bullets to disperse a crowd, the chief of police said Thursday.

Chief William J. Bratton said in an appearance on CBS's "Early Show" that he was "not happy" when he watched videotape of the events at MacArthur Park late Tuesday, when officers fired 240 nonlethal rounds to clear demonstrators.

He said police and news media video would aid investigations into whether the officers' tactics were appropriate.

"We have to really try to determine exactly what happened. We're fortunate in this instance that we have a lot of video to look at," Bratton said. "We have literally hundreds of hours of video to review to make our decisions."

News images showed police hitting a television cameraman to the ground, shoving people who were walking away from officers and injuries from the rubber bullets.

Rally organizers denounced the police action as brutal.

"They were pushing children, elderly, mothers with their babies and beating up on the media" said Angela Sanbrano, an organizer.

The clashes started around 6 p.m. Tuesday, when police tried to disperse demonstrators who moved into a street, according to rally organizers and reporters. Authorities said several people threw rocks and bottles at officers, who used batons to push the crowd back to the sidewalk and then cleared the park.

A police order to disperse was in English and from a police helicopter, a likely ineffective tactic because of the noise and because many at the protest were Spanish-speakers, Bratton said.

Bratton said police were initially trying to deal with 50 to 100 "agitators."

"The individuals were there to provoke police," Bratton said. "Unfortunately, they got what they came for."

Police union leaders urged against a "rush to judgment."

"Our officers gave a legal dispersal order and were met with violence. In the coming days it will become clear what transpired," said Los Angeles Police Protective League President Bob Baker in a statement.

Seven officers suffered minor injuries, and another was pushed off his motorcycle, Bratton said. About 10 other people were treated for minor injuries, though authorities expected the number to rise.

The investigations already under way include an overall departmental review of tactics, an internal affairs investigation into the behavior of the officers and commanders on the scene, and an independent review by the Inspector General, the investigative arm of the Police Commission, which sets policy for the Police Department.

News organizations also condemned the Police Department for its use of batons and riot guns against members of the media.

"We are sorry for what happened to our employees and find it unacceptable that they would be abused in that way when they were doing their job," said Alfredo Richard, spokesman for the Spanish-language network Telemundo, whose anchor and reporter were hurt.

Bratton promised to investigate the treatment of reporters.

The Los Angeles march was one of many nationwide demanding a path to citizenship for illegal immigrants.

Turnout nationwide at Tuesday's rallies was light compared with a year ago, when more than 1 million people took part. And the smaller crowds raised doubts about the future of the movement and its ability to seek changes.

Click here to view photos from the immigration rallies around the United States.

In Chicago, where more than 400,000 people swarmed the streets last year, police put initial estimates of Tuesday's protests at 150,000, by far the largest in the country. In Los Angeles, 25,000 people were on hand for the march. Several hundred thousand turned out in 2006.

Organizers said fear of immigration raids and frustration that Congress has not passed improvements kept many people at home.

Also, last year's effort was galvanized by Republican Rep. Jim Sensenbrenner's proposal calling for felony prosecution of illegal immigrants. Since then, Garcia said, a major division has emerged among immigration advocates over legislation that would give illegal immigrants six years of temporary legal status, but then require them to return home before seeking U.S. citizenship.

"A year ago, we were all against something, and it is very easy to unite people against something," said Joshua Hoyt, executive director of the Illinois Coalition of Immigrant and Refugee Rights. "We all know what we hate but what do we agree on? That's harder."