LONDON — British online supermarket Ocado said on Thursday fire fighters were expected to remain at its complex in southern England for at least the next few days as they continue to bring a devastating blaze under control.

Emergency services have been tackling the fire at the highly automated site full of robots in Andover since the early hours of Tuesday.

"There are still pockets of fire," said a spokesman for Hampshire Fire and Rescue Service.

The complex — which Ocado calls a customer fulfillment center (CFC) — had been providing about 10 percent of the firm's UK capacity and used the robotic technology that it is selling to retailers around the world. The cause of the fire has not been established.

"Since our last update (on Wednesday), the Fire Brigade has continued to work to bring the fire at Andover under control," Ocado said.

It said that due to concerns over the presence of pressurized refrigerants at the site, the police conducted a limited evacuation of the immediate area on Wednesday evening.

The removal of those materials has now been completed and the fire is no longer classified as a major incident, so local residents and workers have been able to access the affected area as normal.

Ocado added it was working to minimize disruption for customers by increasing capacity at its three other major UK facilities in Hatfield, north of London, Erith, near the capital and Dordon in central England.

Ocado's shares, which fell 5.2 percent on Wednesday when the company said the fire would hit sales growth, were down a further 9.1 percent to 881.4 pence at 1135 GMT.

"The question investors have is: 'Does this impact the viability/scalability/cost of the CFCs that they have sold?,'" said Bernstein analyst Bruno Monteyne. — Reuters