Two prisoners escaped from the security lockup ward at D.C. General Hospital yesterday but were apprehended in a nearby parking lot about 20 minutes later, authorities said.

They said Kenneth Bass and Tyrone James were charged with escape after the incident, which occurred about 3:30 p.m. Bass has been convicted of murder and James is serving time for robbery, officials said.

Normally the inmates are housed at the D.C. Jail adjacent to the hospital, where prisoners are routinely taken for treatment of injuries and for checkups, authorities said.

D.C. Jail spokesman Leroy Anderson said he did not know why the men were at the hospital. He said the two men apparently made their way to a holding area between their room and a security gate in the lockup area, overpowered a corrections officer and took his .38 caliber service revolver before fleeing.

That gun was never fired, but another corrections officer fired a warning shot, which did not injure anyone, shortly before the prisoners were apprehended by District police, U.S. Park Police and correctional officers, authorities said.

Anderson said Bass was returned to the D.C. Jail and James, who was bitten by a police K-9 dog, was taken to the hospital for treatment. A hospital official said James was later returned to the jail.