Extra police officers are patrolling streets near the scene of a racially-motivated arson attack in which a grandfather died.
Syed Sorafot Ali died of a suspected heart attack
Bangladeshi couple Abul Kalam Azad and Syeda Sahnaz Begum and their five children escaped from the house in Northcote Avenue, Sunderland on Friday.
But Syeda's father, Syed Sorafot Ali, 76, collapsed from a suspected heart attack after rushing to the scene.
Police said the extra presence was an effort to reassure the local community.
The blaze, in Hendon, broke out in the early hours and the couple had to escape through the rear of their terraced house with their two-year-old son.
Their three others sons, aged 14, 18 and 21, and their 17-year-old daughter escaped by jumping through windows.
Mr Azad said: "My father-in-law collapsed and died because of this incident and I have no idea why anyone would want to do this.
"We are peaceful people living in Sunderland."
Two of the children are still being treated in hospital, but their injuries are not thought to be life-threatening.
Northumbria Police said extra officers and Police Community Support Officers (PCSOs) would maintain a high-visibility presence in the area.
Some of the family jumped from an upstairs windows to escape
House-to-house inquiries are under way and statements are being taken from the occupants of the house in an effort to establish the cause of the blaze.
Det Ch Insp Andy Potts said: "We have a dedicated team of officers who are determined to find the person or people responsible for this fire.
"I would urge anyone who may have any information, no matter how small, to contact police."
Police said a brick thrown through the house's front bay window had nothing to do with the arson attack.
It was thrown by a member of the public who was trying to help those trapped inside.