About 400,000 books have been destroyed in a blaze at a warehouse storing “irreplaceable” editions, according to staff.

£1m-worth of books, including a 150-year-old book signed by Queen Victoria, were destroyed in a fire after flames ravaged through a warehouse in Flintshire at Berwyn Books, Buckley, Flintshire. The warehouse and second hand shop, combined with sister company Cheshire Book Centre, is among the largest online book retailers in the UK.

An investigation into what caused the fire is under way.

Around 30 firefighters tackled the blaze and left the owners of the second-hand shop “distraught”.

Staff at the bookstore have disclosed the number of treasured books that were destroyed in the blaze as members of the community launched an online fundraiser to support them.

Among the items lost in the fire were “real pieces of history,” manager of Berwyn Books Emma Littler told BBC News, including a book signed by Queen Victoria in 1868 and a collection of 30 archaeological books valued at around £5,000 alone.

The fire broke out across two rare book storage units belonging to Berwyn Books and local residents were told to keep their windows and doors shut while motorists were urged to avoid the area.

Historic letters, journals, and bibles were also lost as well as a first edition of the Radio Times from 1923 and around 400,000 books.

Experts have estimated that the total value of the items lost in the fire is £1m.

In an update on social media, staff confirmed the Berwyn Books’ building has now been condemned and was “extremely unsafe” with nobody allowed in except for fire crews.

They added that they “still don’t know what’s going to happen” with the future of the business but “we are and will remain hopeful”.