Army bomb squad officers have carried out a controlled explosion at a school in north Belfast.
Police, paramedics and firefighters were also called out to Belfast Royal Academy on the Cliftonville Road yesterday evening.
The bomb squad was asked to destroy a potentially hazardous chemical.
A police spokesman said: "Police attended a school in the north Belfast area to assist Ammunition Technical Officers safely dispose of a small amount of a chemical compound which had been stored in the premises.
"A controlled explosion was carried out and the material was safely destroyed."
It is understood the chemical compound is the same one the British government warned schools about in 2016/17.
The chemical, sometimes used in chemistry lessons, but can be hazardous if it is allowed to dry out.
