Police in Norway have arrested two teenagers in connection with a series of cyber attacks, including an attack on the UK's Serious Organised Crime Agency (SOCA) website.
Police would not confirm the other targets, but local reports say they include the Norwegian Lottery, Germany's Bild newspaper, the DNB financial services group and Norway's Police Security Service, according to the BBC.
Last week the SOCA website was temporarily unavailable after being hit by a distributed denial-of-service (DDoS) attack.
Security experts said that, although DDoS attacks do not pose a risk to data security, their impact can be massive on the targeted organisation.
The suspected cyber attackers, aged 18 and 19, have been charged in connection with a series of DDoS attacks, but their link to the attack on SOCA is still being investigated.
The attack was the second time in less than a year that SOCA's website has found itself the target of malicious attackers.
In June 2011, members of LulzSec, a spin-off from hacktivist group Anonymous, hit the SOCA website with a DDoS attack.
According to Andrew Kellett, senior security analyst at Ovum, web security is a major area of vulnerability.
High levels of additional spending are needed to improve quality and safety of services, and to ensure the type of attack suffered by SOCA can be dealt with without having to take the site down, he said.