Two men were still being questioned by the RUC last night after an arson attack on a house in Derry in the early hours of Saturday left an 82-year-old woman and her daughter in a critical condition in hospital.
The family was rescued by fire-fighters using breathing apparatus after neighbours spotted the blaze, which started in the hallway.
The elderly woman and her daughter suffered burns and the effects of smoke inhalation, while her son sustained minor injuries and was said to be in a stable condition.
The Catholic family had been living in the house at Bann Drive, in the predominantly Protestant Waterside area, for almost 50 years. The RUC said it was satisfied the fire was the result of a sectarian attack.
Supt Ian Hamill described the attack as "deliberate". It was a miracle the family had not perished, he added.
A local DUP councillor, Mr William Hay, said people in the area had been horrified by the attack.
A Sinn Fein councillor, Ms Lynn Fleming, described the incident as "another step in the efforts of loyalist organisations to create Catholic-free areas". She urged local Catholics to increase their vigilance.