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 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 increasingly on the defensive in the international debate about cyber warfare and cyber espionage. Ten days ago, US cyber-security group 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. The Chinese government and military have angrily rejected Mandiant's accusation, calling the report "unprofessional" and saying that China is one of the main victims of cyber warfare. But the 144,000 figure marks the first time Beijing has backed that assertion with a concrete claim. CNCERT, a cyber-security institution under China's Ministry for Industry and Information Technology, said more than 14m computers in China were hijacked and controlled from foreign IP addresses last year, and more than 10m of those infiltrated machines were under control from IP addresses located in the US. The institution listed South Korea and Germany as second- and third-ranking countries of origin for attackers on Chinese computers. In response to questions, CNCERT said it was unable to identify either victims or attackers. Huawei, the Chinese company which is the world's second-largest vendor of telecom networking equipment, said it was also under constant attack. John Suffolk, the company's chief security officer, estimated that Huawei is attacked about 10,000 times a week. The Chinese government and military have long insisted that they do not sponsor hacking. Information security experts such as Mandiant have linked Beijing to intrusions based on findings that many attacks come from the same telecom networks, and that the software used showed programming patterns used only in China, and appeared to have been created on machines running on simplified Chinese language. In addition, experts in the US argue that the persistent nature of some of the attacks and the targeting of certain industries and particular information suggest a state actor rather than freelance criminals, who are often less careful in covering their tracks and tend to move on quickly. Beijing has strenuously rejected the accusations as attempts to smear China. In an angry editorial this week, the People's Daily, the Communist party's mouthpiece, said: "In fact, it is America which is a real hackers" empire worthy of this name."