YAHOO has been fined £250,000 over a cyber-attack that may have breached more than eight million accounts in the UK, the Information Commissioner's Office (ICO) has announced.

Personal data including names, email addresses, telephone numbers, passwords and encrypted security questions and answers were potentially compromised on about 500 million accounts worldwide during the hack, the ICO said on Tuesday.

The data protection watchdog said the internet giant had "failed to prevent" the Russia-sponsored hack that affected more than eight million accounts relating to UK addresses.