A fire in a Grantham residential street in the early hours of Tuesday morning is believed to have been a suspected arson attack.
Two crews from Grantham fire station were called to the scene in Tennyson Avenue just before 4.40am.
Police attended shortly after.
A Lincolnshire Police spokesman said: “A bag of rubbish leant against an open door to an outside toilet was believed to have been deliberately ignited.
“A fire spread to the roof of the outhouse and Fire and Rescue quickly extinguished to prevent it spreading top to the adjoining property.”
No one was trapped during the incident.
There was severe damage to two outbuildings and their contents, said a Lincolnshire Fire and Rescue spokesman.
Anyone with information is asked to call the police on the non-emergency 101 number, quoting incident number 46 of August 15. Alternatively, call Crimestoppers, anonymously, on 0800 555111.