Homes in South Witham were evacuated earlier as the Explosive Ordnance Disposal team helped Lincolnshire Police investigate chemicals found at an address.
Officers were called to the scene this morning because of a fire.
A 63 year old man has been arrested on suspicion of arson.
A Lincolnshire Police Spokesperson said: “We would like to reassure the community that this incident has been safely concluded. As reported in our initial release, a man was arrested on suspicion of arson. The incident is not terror related.”
“We were called to an address in South Witham at 11.24 am this morning following a fire. There were no injuries reported and a 63 year old man has been arrested on suspicion of arson.
Chemicals were found at the address and some of the rooms were inaccessible.
We would like to sincerely thank the local community for their support and patience as we work to ensure the safety of all. Anyone with any information which could assist us in our investigation is urged to call 101 with reference number 171 of 18 March.”