The UK Intellectual Property Office has taken its website offline due to an ongoing denial-of-service attack.
The IPO said in a statement on Monday that the attack began at approximately 6.00 pm on Saturday.
"The Intellectual Property Office chose to disconnect its website from the internet following a coordinated distributed denial of service (DDoS) attack on Saturday 16th of October at around 18:00 BST," said the IPO in a statement on Monday. "As part of our standard network security procedures, our main services were protected prior to the attack. The website and our internal services suffered no harm. We are preparing to resume services as soon as possible."
An IPO spokesman told ZDNet UK on Monday that the organisation was not in a position to be able to say who had perpetrated the attack.
Operation Payback is a series of denial of service attacks as part of a campaign against pro-copyright organisations.
A recent denial of service attack against solicitor firm ACS Law resulted in data being exposed. The firm is being investigated by UK privacy watchdog the Information Commissioner's Office (ICO) following the breach.