British retailer Marks & Spencer (M&S) has told hundreds of workers not to turn up at its main warehouse distribution centers as it continues to respond to a cyberattack.

It follows the company — which has more than 1,400 stores worldwide and made a profit before tax last year of £672 million ($896 million) — announcing on Friday that it was pausing all online shopping three days after it initially announced it was managing a cyber incident.

Roughly 200 agency workers who had been set to complete shifts at M&S’s logistics centers were told not to come into work, as reported by Sky News, which described the incident as an “escalating crisis.”

A spokesperson for M&S did not dispute the Sky News report. It is understood that shifts have only been cancelled for agency staff, who comprise about 20% of the warehouse workforce, and not full-time M&S employees.

In its latest statement, issued Friday, the retailer said it was “truly sorry for this inconvenience” but told customers its stores remained open.

M&S shares dropped 2% on Monday morning, compounding a 6% drop last week following its notification of the cyberattack to the London Stock Exchange.

The company said: “Our experienced team — supported by leading cyber experts — is working extremely hard to restart online and app shopping. We are incredibly grateful to our customers, colleagues and partners for their understanding and support.”