AN investigation has been launched after a firework was posted through the door of a house in Great Harwood.

Firefighters were called to an address on Heywood Street shortly before 5am on Sunday.

When they arrived they discovered a lit firework had been wedged into the letterbox. Extensive damage was caused to the front door before the firework burnt itself out.

The occupants, a mother and daughter and both of their partners, managed escape the property uninjured.

Detectives are treating the incident as arson and are now appealing for witnesses to come forward. DS Adrian Mc Hugh, of Blackburn CID said: “This is incident could of potentially been very dangerous or even life threatening.

“Luckily all four occupants of the house were able to get out of the property after being alerted to the smoke by the family dogs. I appeal to anyone who was in the Heywood Street area of Great Harwood in the early hours on Sunday morning who saw anything suspicious to come forward and contact police.”

Anyone with information should call police on 101.