A recent wave of hate violence in Montgomery County, targeted primarily at blacks and Jews, has taken its latest toll on a private Jewish school in Rockville which was defaced apparently over the weekend with swastikas and anti-Semitic slogans.

A teacher discovered the vandalism yesterday morning on the building on Bestor Drive which houses both the Children's Learning Center, a nursery school with 200 students, and the Hebrew Day Institute, an elementary school with 100 students. Three large swastikas had been painted on the rear of the building, along with slogans saying "the KKK Ku Klux Klan is Number One" and "Hitler Was Right." One slogan which asked, "How do you spell relief?" was accompanied by a drawing of a rectangle with fumes rising from it, apparently a reference to a gas chamber.

Montgomery County police are investigating the incident, the latest in a series of anti-Jewish activities this month that has included the desecration of a synagogue in Silver Spring and the painting of a swastika on a window of a Jewish delicatessen in Wheaton. Several persons have been arrested in the synagogue case and, if found guilty, could be punished with a maximum of five years in prison or a $5,000 fine.

The schools vandalized yesterday are housed in a county-owned building that was once the English Manor Elementary School. The Children's Learning Center leased the building in 1980, and has been a target of anti-Semitic activities since, according to educational director Renee Popkins.

Within weeks of moving into the building, Popkins said, vandals shattered a new wooden sign, bearing the school's names, which was hung with an existing Engish Manor sign at the front of the school.

In subsequent months, swastikas were painted on walls, on a dumpster, and inside the building by a group of juveniles who were later caught.

The incidents became so bad that the county Human Relations Commission called a meeting of area principals that was attended by county executive Charles Gilchrist, who instructed the county to pay to clean up the building.

There had been no incidents since, Popkins said, until yesterday.

"There seems to be a fine line between what is vandalism and what is an anti-Semitic act," she said. "I feel there is a deeper meaning to it. These recent drawings were very childish but I don't view this as a childish prank. We've tried so hard to keep the building nice. I hate to say this but I just feel that it's not the way to be paid back by society."