A Lower East Side school was evacuated Friday after a student’s boyfriend threatened to come to the building and open fire, law-enforcement sources said.

The student, who attends one of the three schools housed inside 145 Stanton St., alerted the main office to threatening texts and Instagram posts she received from her boyfriend around 1:50 p.m., sources said.

In the menacing messages, the boyfriend said he would come to the school and shoot people, according to a law-enforcement source.

Students were evacuated from the school until the boyfriend was apprehended, the source said.