Two North Side synagogues and one in Lincolnwood were vandalized early Saturday, including one that had "Death to Israel" spray-painted on a wall, police said.
Vandals threw a brick through the front glass doors of Lincolnwood Jewish Congregation, 7117 N. Crawford, around 6 a.m. Saturday, police said.
Vandals also scrawled "Death to Israel" and "Free Palestine" in orange spray paint on the synagogue's outside walls.
Lincolnwood Police Lt. Mark Brines said police were notified at 6:10 a.m. that a caretaker in the building heard a brick crash through a window at the temple.
The caretaker later saw "two unknown males running from the scene," Brines said.
Lincolnwood police believe the vandalism could be related to two similar incidents at nearby synagogues in Chicago.
Chicago Police spokeswoman Antoinette Ursitti said police were investigating early morning criminal damage to buildings on the 2700 block of West Morse and the 6500 block of North California.
Anshe Motele Congregation is at 6526 N California, while Lubavitch Mesivta of Chicago is at 2756 W. Morse.
Officials with those temples could not be reached Saturday afternoon.
"The incidents involved vandalism containing derogatory statements and are being investigated as possible hate crimes," Ursitti said, declining to give more details.
The FBI's Joint Terrorism Task Force has been notified, Brines said.