Two Prince George's County police officers were placed on administrative leave yesterday after they fired shots at two carjacking suspects, critically injuring one, authorities said.

The patrol officers, whom authorities did not identify, were dispatched shortly after 6 a.m. to a BP gas station in the 3200 block of Walters Lane in Forestville after someone at the station called 911 to report that three armed people had viciously beaten a man and stolen his car, police officials said.

About a mile from the gas station, the officers spotted an older-model gold Lincoln fitting the description near Pennsylvania Avenue and Donnell Drive, police spokeswoman Barbara Hamm said. They chased the vehicle a short distance, to a dead-end street in the 3200 block of Forest Run Drive, where the suspects left the car and fled. The officers pursued them into a wooded area, according to police reports.

Hamm said one officer confronted a suspect, who raised a handgun toward the officer. The officer fired one shot, striking the man in the upper body. The man was transported in critical condition to Southern Maryland Hospital, authorities said.

The second officer chased another man into the woods, authorities said. The man fired a handgun and the officer returned the shot, but police did not know whether the fugitive was hit because he was not apprehended. A third assailant, who was seen at the gas station but not in the car, was also at large, authorities said.

"Obviously, we're always concerned when force has to be used," Hamm said. "We're going to investigate the incident thoroughly."

Hamm said that an internal investigation into the shootings was opened yesterday and that details would be released to the public as they became known.

Percy Alston, president of the county police union, called the shooting an "unfortunate result of the ever-increasing level of violent crimes" but said he was "extremely proud" of the officers' response to the dangerous, rapidly unfolding situation.

"They heroically pursued these thugs, and even while we continue to face depleted resources and limited staffing and manpower, our police officers never shirk their duties and responsibilities," he said.

The last officer-involved shooting in Prince George's was last June, when a man -- wearing a cape and carrying two swords and a pellet gun -- refused to surrender and was killed.

In recent years, the department has been the subject of numerous federal investigations that centered on a string of police-involved shootings. A top-to-bottom probe of the department by the Justice Department was completed in January, and county police agreed to many changes to curb excessive force.

Other officers who responded yesterday to the gas station -- in a commercial strip that includes liquor stores, fast-food restaurants and apartment buildings -- found the owner of the Lincoln beaten and bloodied. He was taken to a hospital, where authorities said he was treated and released.

Alston said the police union, Fraternal Order of Police Lodge 89, is concerned not only for its officers who "continue to respond to the violence," but also for residents.

At a news conference last week to announce various crime-fighting initiatives, county officials said that violence in the county has fallen slightly this year.

According to a daily crime report distributed throughout the department, Prince George's has had a 5 percent reduction in carjacking incidents; by Friday, 193 cases had been reported in the county, down from 203 for the same period last year.