Turkish Internet servers have suffered intense cyberattacks last week, according to an Internet management body, raising fears Ankara may be a target of political hackers.

Internet experts said it was not clear who was behind the attacks that began on Monday. But Nic.tr, a non-government body that administers addresses for websites using the ".tr" domain, including ministries, the military, banks and many commercial sites, said they originated from "organised sources" outside Turkey.

Local media reports have suggested a flood of traffic to Turkish internet servers handling more than 300,000 websites, could be coming from Russia. They cited Turkey's soured relations with Moscow after the downing of a Russian warplane last month.

The CEO of STM, an Ankara-based defense technology company operating under the Ministry of National Defense, told Anadolu Agency that Russia might be behind the cyberattacks. Davut Yılmaz reportedly said, "We see Russia using actively all components of cyber power on countries it has problems with. Therefore, the probability of Russia being behind attacks in Turkey, is not low."

The disruptive traffic, known as a DDoS (Distributed Denial of Service) attacks - in which thousands of computers targeted at specific Internet targets - resulted in web speeds plummeting at some sites, Nic.tr said.

"While both the size and duration of the attack are notable, neither is unheard of. We don't have enough information to start speculating on whether this is related to specific countries or which kind of group or single individual may be behind it," said Artturi Lehtio of Finland-based internet security company F-secure.

It is not the first time that Turkish websites have come under attack. The so-called Syrian Electronic Army, hackers loyal to the Syrian government, said earlier this year it had successfully broken into government e-mail accounts.