Officials are trying to determine how an intruder got into an elementary school in Union City, triggering a lockdown for 700 students.

George Washington School in Union City following a lockdown (CBS New York)

Police say the man was found around 8 a.m. Thursday rummaging through a desk in a secretary's office in the basement of George Washington Elementary School.

The school was placed under lockdown as a precaution.

Many of the students' worried parents waited outside until the lockdown was declared over by 10:20 a.m.

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