The lounge of a flat in Tattershall has been severly damaged by fire.
Firefighters were called to the ground floor premises in the Market Place at 10.31pm.
Crews from Woodhall Spa, Billinghay, Horncastle and Sleaford used breathing apparatus and a hose reel to extinguish the blaze.
As well as severe damage to the lounge, there was smoke damage to the rest of the flat.
A spokesman for Lincolnshire Fire and Rescue said on Twitter that the cause is still being investigated.