The FBI has opened a criminal probe into a confrontation involving Prince George's police last week that left an unarmed robbery suspect bitten and seriously injured by a county police dog.

FBI agents are investigating whether a county canine officer violated the civil rights of Donald W. Blankenship Jr., 30, when she set her police dog on him June 10 after he allegedly fought with and tried to run away from the officers, said Special Agent Peter A. Gulotta Jr., a bureau spokesman.

Gulotta declined to say what prompted the investigation. A Prince George's police spokesman said he was unaware of the inquiry and had no comment.

The FBI's probe comes as the federal agency is conducting a related investigation into whether the county's 23-officer canine unit engaged in a pattern of brutality. At least 13 civil lawsuits alleging excessive force by members of the canine unit are pending in Prince George's Circuit Court or U.S. District Court.

In recent weeks, Prince George's police have announced a series of reforms for the canine unit that include changes in training and improvements in the way the department reviews biting incidents.

The FBI's wider probe into the canine unit is a civil investigation, meaning the Justice Department could ultimately sue the police department or reach an agreement regarding training and the use of the dogs. The inquiry into the Blankenship case is a criminal matter; FBI agents will turn their findings over to the Justice Department and U.S. Attorney Lynne A. Battaglia, who will decide whether to seek criminal civil rights charges against an officer or officers involved in the incident.

Police said Blankenship was bitten after he allegedly attempted a strong-arm robbery at Montgomery Ward's in Landover Hills and then allegedly stole money from an open cash register at a Greenbelt gas station just after 11:30 a.m. June 10.

Officers started following a red Dodge pickup and a slow-speed chase ensued. The truck came to a halt after police set up a roadblock in Langley Park, just inside the Montgomery County line, at the intersection of New Hampshire Avenue and Oakview Drive, officials said.

According to a Prince George's County police spokesman, Blankenship, who is 6 feet 2 inches tall and weighs 235 pounds, then stepped out of the truck, fought with officers and tried to run away from them.

At that point, Prince George's police said, a county canine officer released her dog on Blankenship. The dog bit Blankenship on the right arm and inner left thigh.

Videotape shot by WUSA (Channel 9) indicated that Blankenship was bitten near the truck. Footage showed a pool of blood beside the driver's-side door of the pickup.

The leg bite severed an artery, and Blankenship suffered heavy blood loss. He underwent an operation at Prince George's Hospital Center, where he remained for six days before he was transferred Wednesday to the medical ward of the county detention center.

Prince George's police held Blankenship on an unrelated robbery warrant from Montgomery County. This week, they charged him with two counts of robbery and one count each of first-degree and second-degree assault in connection with two June 8 incidents, according to court records.

Police also charged Blankenship with attempted robbery, theft of more than $300 and resisting arrest in connection with the June 10 incident at Montgomery Ward and Blankenship's alleged attack on the officers who tried to arrest him.

At a bond hearing yesterday, Blankenship told Circuit Court Judge Joseph S. Casula that he had not received medical attention at the medical ward of the county detention facility since he arrived there Wednesday.

At the request of Blankenship's attorney, Karl G. Feissner, Casula ordered that Blankenship be transferred back to Prince George's Hospital Center and rescheduled the bond hearing for next Friday.