Five people have escaped injury in an arson attack in the Crawfordsburn area of Maghera that police said could have had disastrous consequences.
Accelerant was poured on the front door of a property in the incident, which happened at around 3am yesterday.
A car was also set alight, with the fire causing minor damage to the vehicle.
Police said all five occupants of the house escaped the attack unharmed.
Detective Inspector Anthony Kelly added: "It is understood that a man described as being 6ft tall and wearing light-coloured bottoms and a grey hoodie was seen in the area at the time.
"Officers believe that he may be able to assist us with our enquiries."
Sinn Fein councillor Brian McGuigan said that while he was thankful no one had been injured in the attack, he was shocked that someone would attempt to set fire to a house in a popular residential area in the middle of the night.
"At this stage no one knows why a family would be attacked in this way," he added.
"It's a worry that an incident like this should target a family's home and their property.
"There would have been residents asleep in their beds in the neighbourhood.
"It could have ended up in a very tragic situation.
"It's absolute madness to see a home attacked in this way.
"I call on anyone who knows anything about what has happened to come forward with information.
"I know the local residents, in what is a long-established and older estate in the town, will have been shocked at the news this morning and will be struggling to understand why a family has been targeted in this way."
Police said they were attempting to establish a motive.
Separately, detectives in Enniskillen are also appealing for information following an arson attack in the Drumbeg area on Sunday night.
It was reported to police at around 11.20pm that there was a fire at a house in the area.
It is believed an accelerant was poured through the door, which was left damaged after the attack, and set alight.
Firefighters attended the scene and extinguished the blaze.