A warehouse used by United Kingdom online supermarket chain Ocado in the town of Andover went up in flames in the early hours of February 5, bringing out over 300 firefighters to put out the fire.

200 firefighters were initially called out to help extinguish the blaze that was first reported on February 5 at 2:44am GMT. Fire crews confirmed that automated packaging machinery was involved in the blaze.

On February 6 the fire escalated, causing 100 residents in the surrounding area to be evacuated from their homes due to fears of possible explosions from a three-tonne cylinder of toxic ammonia gas located in the burning building. The fire service deemed the event a “major incident” and called in additional crews of firefighters. The total number of firefighters working the blaze is estimated to be 300.

Four of the firefighters have been treated for minor smoke inhalation, but no other injuries or issues were reported by crews or staff at the warehouse.

Speaking with the BBC, Hampshire Fire and Rescue Services said the fire was “no longer considered to be a major incident and roads around are the site are open” but said crews would be at the warehouse “for weeks”.