PRAGUE (Reuters) - The past week's sustained digital attack on the Czech Republic continued on Thursday as unknown hackers targeted the internet sites of mobile phone operators, slowing or shutting down the sites.
Hackers have been attacking Czech websites via the flooding technique, known as DDoS (distributed denial of service), since the beginning of the week. The attacks have included major news websites, search engines and the central bank.
The central European country's two leading mobile operators, Telefonica Czech Republic and T-Mobile, said on Thursday that their sites have been flooded by data requests, putting them out of service.
"We registered an attempt for a DDoS attack ... and we have caught it in time," said Hany Farghali, a spokesman for Telefonica Czech Republic.
"However some customers can experience slow displaying of our websites. We have taken preventative steps and are working on complete renewal (of functionality)."
Farghali said the attacks against Telefonica came from Russian IP addresses, which identify individual computers on the internet.
IT experts say that this does not mean that any Russian entity is behind the attack. The attackers may be using networks of infected computers, called botnets, to send the digital requests. The owners of the IP addresses are usually unaware that their computers are part of such a network.
Phone services were not affected by the latest attacks. Vodafone, the third Czech mobile phone provider, said it was not being attacked.
The companies that have come under attack this week have said that attacks came from both domestic and foreign addresses. No group has claimed responsibility and police have begun investigations.
Reporting by Jana Mlcochova, writing by Jan Lopatka; Editing by David Goodman