Fire crews were called to Clinton Terrace at 5.56pm on Wednesday 5th October where some rubbish had been set alight in the back yard of a house on Clinton Terrace.
Damage was caused to a window frame and the fire was put out by 7pm.
A Lincs Fire and Rescue spokesman said that the cause of the fire is believed to be deliberate.
“In the case of any fire, there can be obvious dangers and serious consequences,” said a Lincs Police spokesman.
“Therefore we would encourage people to come forward with information regarding this or similar offences.”
Anyone who witnessed anything suspicious or who has any information can contact Lincs Police on 0300 111 0300. You can also give information anonymously to Crimestoppers on 0800 555 111.