Police are investigating links between several weekend attacks involving petrol and pipe bombs in north Down.
In the latest incident on Sunday, a 62-year-old man was treated by paramedics after petrol bombs were thrown at a house in Newtownards.
There were another two petrol bomb attacks on Saturday, one in Newtownards, another in Bangor.
It is understood there are tensions within a loyalist paramilitary gang and the attacks could involve factions.
The Ulster Defence Association (UDA) was formed during the Troubles but began to splinter into criminal gangs once the conflict ended.
‘Intent to endanger life’
The Northern Ireland Fire and Rescue Service (NIFRS) was called to put out Sunday’s blaze in Moyne Gardens.
A brick was thrown through a front window and two petrol bombs were thrown into the property, which caused fire damage to the window ledge, roof and floor.
Damage was also caused to a car parked outside the property, police said.
On Saturday, a number of windows were broken and extensive damage was caused to the front of a property in Dicksonia Drive, Newtownards.
“Luckily no-one was at home at the time of the attack, which is being treated as arson with intent to endanger life,” said a police spokesperson.
A pipe bomb was thrown at a house in Bowtown Road in the town at about 21:35 GMT on Saturday.
It was reported that a front window and a wall at the property were damaged during the incident.
The property was occupied at the time, but there were no reports of any injuries.
In Bangor, a petrol bomb was thrown at a house in Skipperstone Road on Saturday.
A number of windows were broken and scorch damage was caused to the property during the attack. Three people who were in the house at the time were uninjured.
Police said that attack was being treated as arson with intent to endanger life. They have appealed for witnesses.