A school in the 1500 block of 12th Avenue had copper pipes stolen from a construction site on its campus on Wednesday, Thursday, Friday and Saturday, said Capt. Curtis Lum from the department's Taraval Station.
An employee at Alice Fong Yu Alternative School, a Chinese immersion public school located at 1541 12th Ave., confirmed that the thefts had occurred at their campus.
Lum said in response to the thefts, police have put additional patrols and plainclothes officers in the area. The school also has a security guard, he said.
Police have a description of the suspect, but Lum declined to release it, citing the ongoing investigation.
Then at 5:34 p.m. Sunday, an employee at the French School at 1201 Ortega St. saw two men removing copper rain gutters from a building on the campus, according to police.
No arrests have been made, and police are investigating whether the French School theft was related to the other recent ones, Lum said.
"It is unusual that all of a sudden all these schools are getting hit," he said.
Anyone with information about the thefts is encouraged to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411.