Army Technical Officers are at waste ground near Lurgan’s Victoria St in a operation probing dissident republican activity.
A number of houses had been evacuated this morning in the Lake Street area during the police search but residents have since been allowed to return home.
Dozens of police are combing the waste ground at the corner of Lake St and Victoria Street.
The roads have not been sealed off at this stage.
A PSNI spokesperson said: “Detectives from Serious Crime Branch are carrying out an ongoing investigation into dissident republican terrorist activity.”