A mother and baby were forced to flee their home in north Belfast after arsonists struck overnight.
An oil tanker and shed behind the house at Old Throne Park in the Whitewell district were set on fire. Police are also examining whether any petrol bombs were thrown.
The family got out after being alerted just before 6am.
Rear windows were burnt out and oil flooded over a lawn amid the extensive damage caused by the attack. The flames reached 20ft into the air at the height of the blaze, fire chiefs said.
As police confirmed the fire was started deliberately, the homeowner spoke of his relief that his family was not killed.
Michael McGennis said: "I can't begin to describe how I feel about it. It was total shock, I went through every emotion imaginable. But at the end of the day they were safe — that was the main priority."
Nigel Dodds, Democratic Unionist MP for North Belfast, condemned those responsible. He said: "This is a despicable attack which could have resulted in serious injury or even death.
"Those responsible for this incident do not represent anyone and all right thinking people will be appalled at such a wanton act of violence.