An elderly couple who survived a firebomb attack on their cottage in a Lincolnshire village say they are devastated and baffled.
Peter and Sylvia Cox, 82 and 74, were alerted by their dog, who died in the blaze on Wednesday.
It is the fourth time the home in Castle Bytham has been targeted.
Mr Cox, who investigators said had been lucky to escape the fire, said they could not understand why someone would want to hurt them.
He said: "Police have been talking to us about this and everything we could possibly have thought of we've told them - but we've not really thought of anything which is specific."
The four attacks took place in August, October, March and this month, with the latest one gutting the interior of the 17th Century home.
Mr and Mrs Cox were alerted by the barking of their greyhound Toby as the firebomb was thrown through the letterbox in the early hours last Wednesday.
The couple awoke to flames and dense smoke and managed to escape when neighbours helped them climb from the upstairs window.
They have now been moved to a secret location.
Det Insp David Swan, from Lincolnshire Police, said: "The occupants managed to get out without being seriously injured but obviously the potential was there for them to be seriously injured or worse.
"The family at this time are not able to give us any indication as to why they have been targeted in this manner."
Police said the motive was still unclear and have appealed for anyone with information to come forward.