Murder squad detectives are hoping a brave and emotional public appeal by the aunt of two young children, killed in an arson attack on their home will produce new information.

Nadia Naqui bravely faced the media and wept as she urged anyone "who can bring justice for our children" to come forward.

She described her ten-year-old niece Alina and eight-year-old nephew Aman – who died after a fierce blaze at their home in Hendford Drive, Pollard Park, in the early hours of Tuesday – as "angels" and said "their smiles will be with us forever."

Mrs Naqui, 28, said Aman had aspired to be a footballer and Alina a doctor, but they would never have the chance to fulfil their dreams.

She said they were bright, talented and really good people. "Someone chose to end their lives before they had the chance to live them.

"Aman and Alina made me the proudest auntie in the world."

The children’s mother, Iram Shah, 30, suffered severe burns in the blaze and remains critically ill in hospital.

Detective Superintendent Bill Shackleton, who is leading the investigation, said the children died as a result of the inhalation of fumes from the fire.

He also said revealed that forensic tests had shown that an accelerant, probably petrol, had been taken to the scene of the deliberate fire in a can, bottle, or small container.

The arsonist also took paper, of the type used to wrap fish and chips, to the house. The fire was started against the back door.

Det Supt Shackleton said: "we need to speak to anyone who may know if there is any reason why the Shah family would be attacked."

Police also revealed that an uncle staying with the family had discovered the blaze and, along with neighbours, had tried to rescue the victims.

Det Supt Shackleton said an 18-year-old Bradford man had now been arrested and is being questioned by detectives, along with a 21-year-old man who had already been arrested. They are both being held on suspicion of murder.