A Marine Reservist accused of shooting at military buildings in the D.C. area last fall apparently tried to escape his jail cell by digging through a cinder-block wall, authorities said.

Yonathan Melaku, 23, who is being held at the Loudoun County Adult Detention Center, was charged Monday with damaging his cell to aid escape and possession of an instrument to aid escape.

Kraig Troxell, the Loudoun sheriff’s office spokesman, said that the damage, which was discovered Friday, was “minimal” and that there was no threat of escape through the wall, which is reinforced with concrete.

Troxell said the incident was under investigation. He declined to say what instrument allegedly was used to chip away at the wall.

In response to the apparent escape attempt, the detention center — where Melaku is being held on grand larceny charges involving a rash of vehicle break-ins in Leesburg in May — was placed on lockdown Friday “as a precaution,” according to authorities.

Melaku, an Alexandria resident, also is charged in federal court with shooting at five military sites across the region — including the National Museum of the Marine Corps and the Pentagon — between Oct. 16 and Nov. 2, 2010.