China has countered accusations that its military has been conducting hacking campaigns by saying that its own two main official military websites are under constant attack from within the US.

“Last year, the Chinese defence ministry website and Chinamil.com were attacked 144,000 times a month on average,” said Colonel Geng Yansheng, defence ministry spokesman. “Attacks originating in the US accounted for 62.9 per cent.”

The statement comes as Beijing finds itself on the defensive in the international debate about cyber warfare and cyber espionage. Ten days ago, the US cyber-security firm Mandiant named one particular unit of the People’s Liberation Army in Shanghai as the likely perpetrator of a six-year sustained hacking campaign against more than 140 companies across the globe. In past months, several US news organisations have revealed that they were hacked following investigative reporting on the Chinese leadership.