Charlestown High Among Schools to Receive Suspicious Letters

Charlestown High School was among the Boston Public Schools that received suspicious letters on Thursday.

As of Friday afternoon the Boston Police Department had collected 24 suspicious letters sent to educational institutions around the city, according to BPDnews.com.

"There does not appear to be any reason why any particular schools received letters and it is possible that others have yet to arrive. The letters all appear to be from the same sender and have the same postmarked Texas address. The investigation is ongoing," the BPDnews.com posting states.

Boston Police increased presence at schools across the city on Thursday and Friday, and police have said there is no credible physical threat. The letters did not contain any dangerous substances.

These are the schools that received letters:

Adams Elementary School
Beethoven Elementary School
Boston Community Leadership Academy
Boston International High School
Boston Latin Academy
Charlestown High School
Community Academy of Science and Health
Dorchester Academy
Edison K-8 School
Fenway High School
Gardner Pilot Academy
Henderson Elementary School
Irving Middle School
Mather Elementary School
McCormack Middle School
McKinley South End Academy
Murphy K-8 School
O'Bryant School of Mathematics and Science
O'Donnell Elementary School
Ohrenberger School
Quincy Upper School
Roger Clap Innovation School
Russell Elementary School
Tobin K-8 School