Four homes could be uninhabitable for weeks after arsonists in Co Tyrone set fire to nearby oil tanks.
A wheelie bin was pushed against property in Ratheen Avenue, Cookstown, and set alight causing substantial damage, chairman of Cookstown council Tony Quinn said. Two houses and two flats were affected.
"This is very sinister and I am thankful that nobody was injured in this attack," he said.
According to Mr Quinn, people could be out of their homes for up to eight weeks.
"This is a disastrous way for families to start the new year," he added.
A Police Service of Northern Ireland spokesman said the alarm was raised shortly before 6.30am on Friday and fire crews dealt with the blaze. Three oil tanks were destroyed and the buildings suffered fire damage.
The spokesman added: "Police believe the fire was started maliciously and are keen to hear from anyone who can help identify youths seen in the area in the hours before the blaze was reported."
A Housing Executive spokeswoman said: "We have not yet been able to access the properties as they remain cordoned off. As soon as we have access to the site the assessment of the damage is a priority.
"We are, at the present time, working with the families concerned to ensure they have accommodation to go to tonight and until they can return to their homes."