Two men are in custody after police received two reports of a man making threats to school children, parents, and teachers on Cathedral Drive in Spalding.
The first incident was reported at 8.48am and the second at 9.11am today.
Armed officers were deployed to the scene and the junction of Cathedral Drive and Park Close was closed shortly before 9.30am.
Following further investigations, two men, aged 45 and 56, were found in the property and they were both arrested in connection with the incident. They are currently in police custody.
Officers are working closely with Spalding Primary School to ensure the safety of children and staff.
Enquiries are ongoing.