A blaze which extensively damaged six houses may have been started deliberately, police said.
An oil tank caught fire at Ballyfore Road in Newtownabbey on Saturday evening, the Northern Ireland Fire and Rescue Service (NIFRS) said.
Firefighters from Glengormley and Belfast wearing breathing apparatus used five firefighting jets to stop the spread of the flames to any other properties.
PSNI Detective Constable Chris Perks said: "The fire extensively damaged six homes and we believe it may have been started deliberately.
"We would ask anyone who was in the area between 5-6pm this evening and saw any suspicious activity to get in touch with police."
Firefighters were also involved in containing 2,000 litres of domestic oil to limit the impact of environmental damage.
NIFRS had seven pumping appliances, an aerial appliance, a command support vehicle, welfare vehicle and 50 people at the incident.
Its statement said: "Thankfully on this occasion the swift response from firefighters has prevented any serious injury, loss of life or further fire spread to adjacent properties."