U.S. Army Corps of Engineers said about 50 23-pound bombs, several rockets, a rocket booster and a cannon have been found buried near Odyssey Middle School since Dec. 27.
Army workers detonated the found explosives in pits over the weekend after finding a World War II-era tank underground.
“If you can picture this, a World War II tank is physically located in one of these pits,” an official said.
“This shows how urgent this is,” said Orlando City Commissioner Phil Diamond. “I don’t know if everyone has grasped the magnitude of this.”
Part of the school grounds was used by the Army in the 1940s to train bombardiers for combat.
The Army Corps announced its cleanup of the area during the summer.
Local authorities reported that three small areas on school grounds still have to be checked for munitions.
However, school leaders and the Army officials said children at the school are safe.
When the search is done, the Army Corps of Engineers will focus on neighborhoods surrounding Odyssey Middle School.
The neighborhood search could take months to complete, local authorities reported.
“We won’t allow anyone to do any digging,” Orange County Public Schools representative Dylan Thomas said. “As long as no one does any digging here on the property, it is perfectly safe.”
In November, a nearby street was evacuated when a contractor uncovered a 23-pound bomb two feet underground in a lot near a vacant home.
The city of Orlando cancelled all building and construction permits and halted construction in the neighborhood last month.