Vandalism that led officials to a small, private Jewish secondary school to board up their school building in Wheaton last fall and rent space for classes elsewhere culminated last month in a deliberately set fire that gutted the vacant building.

Parents and officials of the Yeshiva High School of Greater Washington said yesterday that the vandalism included swastikas, anti-Semitic slogans and obscene words scrawled on walls and blackboards, and the destruction of religious articles and books.

The boarded-up one-story school at 11801 Kemp Mill Rd. was burned out March 25 in a fire that Montgomery County fire investigators say was the result of arson.

Although the building was again boarded up after the blaze, the vandalism apparently is continuing.

A reporter easily entered the school yesterday because the plywood strips covering a door and a window had been ripped off. A blackboard contained a chalk-scrawled swastika, a racial slur and several obscenities.

Tzivia Bramsom, who has two daughters attending Yeshiva, said the plywood strips had not been ripped off last Friday when she drove past the building.

A county police spokesman said the department has received reports of seven incidents of vandalism there during the last two years. No arrests have been made so far, he said.

A county public school spokesman said yesterday there have been no serious reports of vandalism at the five public schools in the Kemp Mill area.

Mrs. Bramson and Gilbert Ginsburg, a parent and member of the Yeshiva school board of directors, said the vandalism and five had had "a harsh economic impact" on the school.

Ginsburg said the school is paying a total of $15,000 in rent for the two separate locations where the 63 male and female students attend classes, in addition to paying off the $32,000 mortgage on the burned building.

Ginsburg said school officials had planned on renting the building out and, before the fire, were scheduled to sign a lease March 28 with an non-sectarian group that wanted to operate a day-care center there.

"The fire wasn't an isolated incident and it wasn't an accident," said Ginsburg, a George Washington University law professor who has two sons at Yeshiva. "It's just the latest in a series of things that's been going on for a long time. It's very disquieting."

The vandals have always struck on Friday night, which is the beginning of the Jewish Sabbath, or early Saturday morning, Bramson and Ginsburg said.

Ginsburg recalled that about two years ago - the county police, in effort to catch the vandals, posted an officer with a guard dog inside the school on a Friday night.

The policeman and the dog left at 6 a.m. Saturday after an uneventful night, Ginsburg said. By the time several faculty members arrived at 8, the school had been vandalized again, he said.

"It was obvious to us then," Ginsburg said, "that these weren't random attacks, that someone was watching the building."

Yeshiva was organized 13 years ago, Ginsburg said, and has held classes at several different locations in Washington and Montgomery County. The Kemp Mill building and the 3/4-acre property on which it stands is the first property the school has owned.

Students attending the three-years high school get a half day of religious instruction as well as a full secular secondary educational program.