A 20-week-old fetus was discovered Monday morning under a tree in Brooklyn across the street from a park and a junior high school, police said.

The fetus was found by a woman passing by shortly before 7 a.m. in the area of Linden Boulevard and Bradford Street in East New York, just feet away from George Gershwin Junior High and Linden Park.

EMS pronounced the unborn baby dead at the scene, said police, adding they were not yet able to determine a gender. The only clue to what may have happened was a bag of bloody clothes discovered near the remains, a witness said.

“It’s crazy. It’s unbelievable. Shocking and disheartening,” said Veronica Sexton.

“I came in and told my mother, there is a bag with bloody clothes, I’m gonna call the cops, it doesn’t look right. She came outside to look at it and she said to just leave it.”

Other bystanders said they hadn’t noticed the tiny body Sunday.

Orlando Reid, who lives in the neighborhood, said he first saw the fetus around 5 a.m. while out for a walk.

“There was no blood around it, so she didn’t have it there,” said the 42-year-old. “It’s a sad case. I wish whoever the woman that did it, did it differently. Hopefully, the person whose child it is gets help.”

“This is a quiet block, a good block.”