Luxury department store Harrods said it was the latest target of cyber attacks.

The company said it “restricted internet access to our website” after trying to access its systems.

This is the second day after the co-op shut down part of its IT systems to fend off hackers, while Marks & Spencer continues to handle cyber attacks, which cost IT millions of pounds of sales.

Harrods said its flagship store remains open and continues to operate its online sales.

Harrods did not clarify the scale of its impact on the network, but said customers were asked to "not do anything different at the moment."

"We have recently experienced unauthorized access to some of our systems.

“Our experienced IT security team immediately took positive steps to ensure the system is secure, so we restricted internet access on the website today.

“Currently, all websites including our Knightsbridge Store, H Beauty Store and Airport Store are still welcome to open. Customers can also continue shopping through Harrods.com.”

Harrods' online store appears to be operating normally on Thursday night.

Richard Horne, CEO of the National Cybersecurity Centre (NCSC), a British government agency responsible for supporting cyber threats, said a series of attacks should serve as a "wake-up call" for Harrods, co-ops and M&S.

He said the NCSC is working closely with the companies reporting the incident “to fully understand the nature of these attacks and provide expert advice to the broader sector based on the threat chart.”

Cody Barrow, former head of the NSA cybersecurity agency, now CEO of cybersecurity company EclectiCiq, said the incident exposed “increasing cyber threats” to the department.

He said retailers should assume that they are targeted by cyber attackers due to the high impact of customer data and their destructive effects.

He added: “It is crucial for consumers to be vigilant: update passwords, monitor financial activity, and take care of taking advantage of recent violations of scams.”

The company revealed last week that Marks and Spencer's operations were severely hampered by cyber attacks.

Customers are still unable to place online orders and the shelves are empty in some stores.

Police are investigating.

Meanwhile, the co-op said Wednesday that it had shut down its IT system in part to respond to hackers trying to access.

On Thursday, staff at the cooperative were ordered to keep cameras at remote work meetings and verify all attendees.

Experts say this suggests the company suspects that hackers might be lurking on the phone.

It is not clear whether these three events are connected.

Toby Lewis, head of threat analysis at cybersecurity firm Darktrace, said the three incidents affecting M&S, co-ops and Harrods could be a coincidence.

But he raised two other possibilities: All three retailers shared a normal supplier or technology that had been compromised and used as a hacker portal.

Or the scale of the attack on M&S prompts other retailers’ security teams to look more closely at their security logs and take action on activities that they had not previously judged for risk.

“This is a lesson for large organizations to ensure threats in their supply chains, especially as the number and complexity of these threats grows,” he said.

It is believed that M&S's sabotage is a ransomware attack.

This is a malware that is used to piece together important data or files after accessing a computer system, locking it up unless the ransom is paid.

Security experts told the BBC on Tuesday that a ransomware group was named "Dragonforce".

The cooperative did not give any details on the nature of the cyber attack.

Liam Byrne, chairman of the Parliament’s Commerce and Trade Commission, has written to Stuart Machin, CEO of Marks and Spencer, for a cybersecurity defense regarding M&S and whether it complies with NCSC guidance.