Two police officers who helped save residents from a flat fire in Antrim were treated in hospital for smoke inhalation.
The fire broke out at the Tigers Court property at around 1.30am on Friday.
None of the residents suffered any injuries but police have appealed for anyone with information to contact them.
Inspector John McDowell said: "As a result of evacuating residents from the building, two police officers were treated at hospital for smoke inhalation."
He added: "I would appeal to anyone who may have noticed any suspicious activity in the area to contact police at Antrim on the non-emergency number 101. Or, if someone would prefer to provide information without giving their details, they can contact Crimestoppers on 0800 555 111."
Meanwhile, in a separate incident three people were led to safety after a fire broke out at a hostel in Belfast.
The Fire and Rescue Service was called out just before 1.30am on Friday to Ormeau Centre hostel in Verner Street. One person was taken to hospital as a precaution.