Update: The Globe reports the letters have rambling references to al-Queda, Nazis and "poisonous organs in animals."

Among the schools receiving letters: Beethoven, Ohrenberger, Kilmer and Lyndon in West Roxbury, Irving and Bates in Roslindale, BTU Pilot School in Jamaica Plain, Charlestown High School, Dorchester Academy and the Harbor School.

BPS is robocalling parents this afternoon with a vague message that several schools got "suspicious" letters today. Remain calm, BPS says, but expect added police presence at city schools, just in case.

In a statement, BPS and Boston Police say the schools got similar letters, all postmarked in Texas: