A nine-week-old baby was one of five people killed in a house fire in Sheffield, along with two women and two other children.
A cousin of one of the women said the other two children were aged nine and seven.
He said the two women who died were his 54-year-old cousin and her 20-year-old daughter - the children's aunt.
More top news
Police have stepped up patrols after the suspected targeted attacks.
The royal couple will carry out their first official engagements as husband and wife on Tuesday.
Flights from UK airports were an average of 15 minutes late in 2017.