The US military is increasingly concerned about cyber-espionage and cyber attacks as hackers across the globe attempt to steal military information, according to the head of US Strategic Command.

General Kevin Chilton, whose command is responsible for offensive and defensive cyber operations, said the military faces more than a million "hits" on its networks every day. While some represented nothing more than curiosity on the part of citizens, he said the military was concerned about espionage and threats from terrorist groups such as al-Qaeda.