(CNN) -- South Carolina Highway Patrol officers have been caught on dash-cam video hitting African-American suspects with patrol cars, and using a racial epithet during at least one pursuit, a U.S. attorney said.

Dash-cam video captures a suspect running away from a patrol car that is chasing him.

One officer is heard on tape saying he intentionally hit a suspect, Kevin McDonald, acting U.S. attorney for South Carolina, said Thursday. The FBI is looking into the allegations, he said.

"I felt it was important the FBI look further into it. And because of the nature of the tapes, I thought it was important for the Civil Rights Division of the Justice Department to be brought into it," McDonald said.

The South Carolina Department of Public Safety welcomes the investigation, spokesman Sid Gaulden said.

"I think any investigation will clearly show there's no systemic pattern of misconduct," he said. "I am not defending these incidents, but the number is small. If there was a pattern of misconduct, it would have come to light."

In one video, dated June 24, 2007, Lance Cpl. Steven Garren strikes a suspect running away during a pursuit at night. The man slides onto the hood of the car before landing on the roadside.

In an exchange with another officer afterward, Garren is heard saying, "I nailed the f--- out of him. He went flying up into the air."

Someone is heard asking, "You hit him?"

Garren responds, "Yeah, I hit him. I was trying to hit him." Watch men being chased and an officer saying he intentionally hit a man »

In another video, dated April 28, 2007, Lance Cpl. Alexander Richardson chases a suspect through an apartment complex. Richardson drives his car over the sidewalk, across the grass and through a common area as other people scramble to get out of the way.

At one point, Richardson briefly strikes the man with his car, causing him to stumble before he resumes running.

Gaulden said both troopers violated department policy by using cars to chase suspects who were on foot. Garren, he said, received a three-day suspension, which he has completed but is appealing. Richardson was reprimanded and completed a stress management course.

Two highway patrol bosses left their jobs after a third video emerged of a December 2004 incident. In that video, Lance Cpl. Daniel Campbell can be heard telling a running suspect, "You better run, [racial epithet], because I'm fixing to kill you."

Campbell was reprimanded, suspended and ordered to undergo anger and diversity training, Gaulden said.

But South Carolina Gov. Mark Sanford believed stronger action should have been taken.

Sanford released a statement saying his administration "has always been about setting a higher bar and a higher standard for how state government goes about the business of protecting and serving the people of South Carolina."

"When someone disregards that standard -- or, worse yet, exhibits behavior that is absolutely intolerable, no matter the situation -- we expect the leaders we've appointed to take swift and meaningful steps to correct it."

McDonald said Thursday that he could not say whether the federal investigation would focus only on the troopers in the newest videos or extend to last month's departures.

He said the Justice Department and federal prosecutors would wait to hear from the FBI before deciding whether charges would be filed.

Highway patrol tapes are routinely reviewed, Gaulden said.

Disciplinary action is taken when inappropriate behavior occurs, he said.

"You want to stop it," Gaulden said. "One time is too many. Action is designed to get the individual's attention and change behavior." E-mail to a friend

CNN's Carol Cratty contributed to this report.