A major incident has been declared as firefighters tackled a huge fire at an industrial estate in Northamptonshire.

A plume of smoke was billowing over the Sanders Lodge site in the town of Rushden on Friday, leading emergency services to warn people to close their doors and windows as they battled to stop the flames spreading.

Firefighters said they expected to be on the scene into the bank holiday weekend. The burning building had been fully evacuated, as were those surrounding it, and everyone expected to be inside had been safely accounted for, they said.

Mick Berry, the area manager for Northamptonshire fire and rescue service, said the “large fire” had had a “significant impact on the Sanders Lodge industrial estate in Rushden”.

He said a multi-agency decision was taken to declare a major incident, but “fire crews are working extremely hard to prevent the fire from spreading and reduce the smoke plume”. That status was downgraded later on Friday afternoon when firefighters said the blaze had been brought under control and contained within the site.

Nevertheless, people were warned to stay away and keep windows and doors shut. Berry said he appreciated the impact this was having on local businesses and wanted to thank them for their patience.

The fire started shortly before 6.30am on Friday and crews worked throughout the day to prevent it from spreading, Northamptonshire fire and rescue said. It said the fire involved a large quantity of plastic.

The fire service support had been sent from Cambridgeshire and Bedfordshire, though these firefighters had been sent home by Friday afternoon.

Northamptonshire fire and rescue said gas to the site had been isolated and they had worked with North Northamptonshire council and the gas company Cadent to prevent supplies to about 500 nearby properties from being cut off.