Unexploded mortars, possibly from World War I, found and detonated at airfield in Washington state

Multiple unexploded mortars were found and safely detonated at an airfield in Washington State, authorities said Thursday. 

The Vancouver Police Department said that the ordnance was found by an archaeologist at Pearson Field Airport shortly before noon Wednesday. 

Once police were made aware of the unexploded ordnance, the department's Mobile Explosive Device Unit responded to assess the situation. U.S. Air Force Explosive Ordnance Disposal personnel were also called to assist, the department said.