A couple fled their home after their front door and car were deliberately set on fire.
The 62-year-olds were not injured in the attack on Balvenie Street, Coatbridge, North Lanarkshire but their house and car were damaged.
Police said the incident took place at around 11.50pm on Friday.
Detective Sergeant Clare Cassidy said: “Thankfully the occupants of the house, a man and a woman, both aged 62 years, were not injured, however, this was very frightening for them and if they hadn’t heard the noise outside and called the emergency services so quickly, this could have been so much worse.
“Whilst we don’t think this was a random attack on the property, at the moment were are still trying to find out why this house and car was targeted.
“Witnesses report seeing three or four people wearing dark clothing making off from the incident.
“Officers are checking CCTV and carrying out house to house enquiries but would ask anyone who was in the area at the time, maybe driving in the street and their cars have dash-cam footage, to get in touch.
“As I said, thankfully no-one was injured but to be so reckless as to throw accelerant at a home knowing people were in is shocking and we need to catch those responsible.”