The firework was caught in the letterbox and sprayed sparks into the hallway for several minutes.

The incident happened at the family's home in Swinburne Road, Wellingborough, at 8.25pm on Saturday.

Police are investigating the incident.

Marie Davies, 29, was putting daughters Ann-Marie, six, and Fay, five, to bed when she heard a noise.

She said: "I thought someone was knocking at the door and started walking towards it. My friend said it was a firework, and it started going off in the house.

"Our dog ran into the sparks and if someone had been standing right by the door they could have been seriously hurt. I was really scared and the kids were screaming."

The firework has left the letterbox and the door damaged.

The firework incident follows a burglary at the house in August and an attack on the family's car.

She said: "I am worried I might be being made a victim."

Her former partner John Anderson, 20, of Winstanley Road, who is the father of her unborn child, said: "I think it was kids trying to have a laugh but trying to have a laugh with a firework is dangerous."

Northamptonshire Fire and Rescue group manager Barry Mullan said: "We deplore this type of activity. There are people who are seriously injured every year as a result of fireworks and, apart from being anti-social, this sort of thing is also a crime."

Queensway Ward councillor David Dean said: "It was a senseless episode which could have been extremely dangerous. It was an appalling incident."

Chief Insp Max Williams said: "We have launched Operation Vector to target people who take part in anti-social behaviour during the period including Diwali, Halloween and Bonfire Night."

Witnesses can call the police on 08453 700700.