Internet security firm Radware has issued a threat alert which says that Nato countries, particularly the UK, Germany and France, along with the USA should increase their readiness levels to cope with any such incidents.

It made its warning following the actions of separatists in Ukraine, which are agitating to secede and join Russia.

The warning from Radware said: “This conflict takes a global form following the involvement of the USA, Europe, NATO and other actors.

"This threat alert calls for multiple countries and organizations to be prepared for cyber-attacks and possibly even cyber-war as a direct result of this global conflict. The reason is simple: cyber attacks nowadays accompany physical and political conflicts."

It said that all government agencies, the financial sector, utilities and infrastructure, news sites, and e-commerce sites could all be under threat.

It added: “Based on past experience, these attacks may include DDoS attacks, site defacements, intrusion and data theft  attempts, and possibly even attacks on critical infrastructure.”

The attacks, it said, could be carried out by “hacktivists” or by professional organisations with government or policital associations.

The company said it had seen a surge in DDoS attacks in Ukraine in the last few days, both DNS and NTP reflected floods causing pipe saturation, although it said it has no evidence they were related to the conflict.