By David Ljunggren and Alastair Sharp OTTAWA/TORONTO (Reuters) – The recent hacking attempt on a sensitive Canadian government computer network is similar to attacks mounted by an elite unit of the Chinese army based in Shanghai, according to a cybersecurity expert. Canada said on Tuesday a highly sophisticated Chinese state-sponsored actor had broken into the National Research Council, a leading body that works with major companies such as aircraft and train maker Bombardier Inc . Beijing on Thursday accused Canada of making irresponsible accusations that lacked credible evidence. While Canada did not give details of the attack, CrowdStrike Chief Technology Officer Dmitri Alperovitch said it was similar to other hacking campaigns launched by a unit of the Peoples Liberation Army that his company has nicknamed Putter Panda. The group, Unit 61486, has thousands of people and conducts intelligence on satellite and aerospace industries, he said.