TIOGA (WPVI) -- A Philadelphia high school has been locked down after threatening text messages were sent to three staff members.
It's happening at Simon Gratz High School on West Hunting Park Avenue in Tioga.
Mastery Charter School officials say the lockdown went into effect at 8 a.m. Tuesday, after three staffers reported receiving threatening text messages on their cell phones overnight.
No injuries were reported.
Administrators ordered the lockdown, and Philadelphia police were called.
Officials say the phones are now being examined by police.
39th District police officers are at the school investigating, along with members of the police department's Homeland Security Division.
Stay with Action News and 6abc.com for more information as it becomes available.