Students in two communities discussed a suicide pact and possible school shooting on Facebook, resulting in the arrests of two high school teens in Tewskbury, New Hampshire, and Winthrop, Massachusetts on Thursday. Manchester, N.H. police were alerted by a concerned citizen who saw the Facebook message. Two teenage girls are in custody as a result.

The incident began with a Facebook posting from a female high school student in Tewksbury, saying that she wanted to “get two guns” and “make a suicide pact.” A female Winthrop student responded, saying “can we shoot up schools first tho.” The first student posted back “YO lets do it.”

Tewksbury police responded, working with the school department staff to locate the first student, who was removed from school and “secured,” according to Tewksbury Police Chief Timothy Sheehan. Sheehan said “she is getting the appropriate care at this time.” Tewksbury police notified Winthrop police, who were able to locate Massachusetts student before she arrived at school. Winthrop High School was in a 1-hour “hold in place” while police investigated.

Winthrop Police Chief Terrence Delehanty said that they take all threats seriously, as they are not willing to risk the safety of children or communities, as “we don’t know anyone’s potential.” Four schools were identified in the threats: Winthrop, Tewskbury, Woburn and Manchester. Delehanty said that an investigation is ongoing with the other communities involved.

Law enforcement customarily monitor social media to spot potential crimes. Winthrop Detective Brian Perrin said at a news conference that there are many threats, and a lot of cyber bullying nationwide.

No charges have been filed, although investigators are consulting with the district attorney’s office in Middlesex about possible criminal charges.