A website blamed for launching more than four million cyber-attacks around the world, including attempts to crash banks in the UK, has been taken down in a major international investigation.

The operation, which involved the UK's National Crime Agency, blocked Webstresser.org - which allows criminals to buy attacks on businesses.

The site was used by a British suspect to attack high street banks last year, causing hundreds of thousands of pounds of damage.

Six suspected members of the gang behind the site have been arrested, with computers seized in the UK, Holland and elsewhere.