Firefighters dealt with a 'major' and 'complex' blaze in which a number of houses were badly damaged on Saturday night.
The Northern Ireland Fire and Rescue Service said they sent seven pumps, one aerial, one command unit and one welfare vehicle and 50 personnel to the incident at Ballyfore Road, Newtownabbey.
These images show the scale of the blaze.
The PSNI has appealed for anyone who saw any suspicious activity in the area between 5pm and 6pm to get in touch.
Police said said one man was treated at scene for smoke inhalation and that six homes were badly damaged.
Police said: "Detectives investigating the cause of a major fire in Ballyfore Road, Newtownabbey this evening appeal for anyone who saw suspicious activity in the area between 5-6pm today to contact police on 101 or Crimestoppers anonymously on 0800 555 111."
Paul Hamill, the mayor of Antrim and Newtownabbey Borough Council, tweeted: "Serious #fire in Ballyduff with a number of properties destroyed. Thankfully no one hurt.
"Huge appreciation and thanks to all the Emergency services and especially the Fire Service for their courage and bravery to bring it under control."