Last Updated 1:39 p.m. ET
ELMONT, N.Y. Students at Elmont Memorial High School are resuming normal activities after reports of a suspicious person put the school in lockdown, CBS Station WCBS reports.
The lockdown was put into effect shortly after 8 a.m., in response to a 911 call from a woman who said she saw a male teenager with a backpack and a lime green gun. Police said the gun was likely a toy, but took precaution in light of the Sandy Hook Elementary shooting in Newtown, Conn., last month.
No injuries have been reported.
Nassau County Police were guarding the entrance of school for more than three hours. SWAT teams were also seen in front of the school building.
Radio Station WINS reports students were kept in classrooms with locked doors and the lights turned out. Some students were turned away because they were arriving at school as the lockdown was beginning, but worried parents began congregating around the school because their kids are still inside.
WINS correspondent Glenn Schuck reports police helicopters also searched the surrounding area by air.
Parents received "robo-calls" notifying them of the situation.
One parent who showed up at the school told Schuck she has been in touch with her child, who told her the students are huddled in corners of their rooms with the lights out before things returned to normal.