An infant girl believed to be less than 2 days old was found abandoned in a cardboard box yesterday behind the Hebrew Academy of Greater Washington in Silver Spring, Montgomery County police reported.

The baby, weighing just over 6 pounds, was discovered at 10:45 a.m. on a patch of grass alongside the school after a school receptionist received a call from a woman with a foreign accent who pinpointed the location of the box, police said.

A school custodian who went looking for the box found it under a tan trenchcoat in an area behind the school where paper trash is collected, police said. The baby was wrapped in a sheet in a 12-by-18-inch box that had been lined with newspaper and plastic, according to police.

School officials notified police, who then transported the infant to Holy Cross Hospital where it is listed in good condition. The baby was examined and fed at the hospital and its umbilical cord was tied, according to Holy Cross spokesman Tom Burke. The infant's umbilical cord already was cut when the baby was found, but was improperly tied, Burke said.

It is unknown how long the baby lay outside the school, but a custodian told police he recalled seeing the box around 8 a.m., but did not check to see what was inside.

This is the first case of an abandoned child this year in Montgomery County, according to police. The last case was two years ago when a child was abandoned by its mother in the Colonial Manor Motel on Rockville Pike, according to Sgt. James Bohn of the Juvenile Division. He said the mother later was located.

"But in this case, we have so little to go on," Bohn said. The child will be turned over to the County Social Services Department, which will place it in a foster home, a department spokesman said. Laurie Richardson, a department official, said that the baby may be put up for adoption later if its parent are not found.