By Steve Beck

WILMINGTON, Del. (CBS) — A high school in Delaware was placed on lockdown after two threatening phone calls, including one that mentioned a bomb, were placed Wednesday morning.

The incident happened at the John Dickinson High School on Milltown Road in Wilmington.

According to the Delaware State Police, at about 8:10 a.m., an unknown male called the school’s main office and said that he was en-route to the school in order to detonate a bomb.

Three minutes later, police say a second call was placed by the same male to the Wilmington Police Department’s emergency call center advising that he was en-route to the high school and was armed with guns.

The school’s administration immediately placed the school in a lockdown status.

Delaware State Police K-9 units responded to the school and conducted a search of the building, which was eventually cleared with nothing out of the ordinary located.

The school resumed normal operations shortly after 10 a.m.

As a precaution, Delaware State Troopers will maintain an increased presence at the school for the remainder of the day.

Anyone with information is urged to call 302-633-5000 or Delaware Crime Stoppers at 1-800-TIP-3333.