A Washington Post reporter, after interviewing several youths in Quantico about the town's new curfew for juveniles, was arrested late Friday night for allegedly contributing to the delinquency of a minor.

Michael J. Ybarra, 23, a reporter with The Post's Metro staff, was taken into custody about 11:15 p.m. in the Olympia Restaurant on Potomac Avenue, where he was talking with two 12-year-old boys. The arresting officer was identified as Quantico Police Sgt. William J. Unrine.

Responding to a recent spate of vandalism, the Town Council in Quantico, about 30 miles south of Washington, passed a curfew this month forbidding youths under 18 to loiter on public or private property from 10 p.m. to 6 a.m.

Leonard Downie Jr., managing editor of The Post, said yesterday that the arrest appeared unwarranted and objected to the fact that police confiscated notes Ybarra had taken of his interviews with youths.

"Based on the information we have, the arrest of a Washington Post reporter while he is reporting a story and breaking no law himself appears unwarranted to us," Downie said. "I'm particularly concerned that the police pursued this after the reporter identified himself and his purpose, and that the police took his notes."

Quantico Police Chief Leo Rodriguez described the case as a routine arrest. "I believe that the reporter was trying to do his job and just got mixed up at the wrong place at the wrong time," Rodriguez said. He said Ybarra's notes would be held as evidence, but that a copy of the notes would made available to The Post.

Although no youths have been arrested for violating the new curfew, Ybarra is the second adult charged with contributing to the delinquency of a minor because they were present with youths after the 10 p.m. cutoff time.

Ybarra, who was released on his own recognizance, will be arraigned Tuesday morning in Juvenile and Domestic Relations Court in Prince William County. If convicted, he faces a maximum penalty of one year in jail and a fine of $2,500.