The People's Liberation Army has carried out a second, albeit unsuccessful test of a hypersonic vehicle, two sources close to the military said, as China attempts to find a way to deliver nuclear weapons at immense speed to evade defence systems.
The test was carried out on August 7 at a missile and satellite launching centre in Shanxi province, about 300 kilometres from its capital Taiyuan, said the sources, who asked not be named.
The vehicle broke up soon after it was launched. It was the second time the PLA has tested the system, the two sources said.
The first test took place on January 9, and it was confirmed by the National Defence Ministry as successful a few days later.
The latest model is designed to be carried by a ballistic missile to an undisclosed suborbital altitude, then released. The vehicle then dives towards its target at speeds of up to Mach 10, more than 12,000km/h.
The United States is the only other nation known to have developed similar technology. China first tested the technology successfully in January. Russia and India are also known to be developing similar vehicles.
The defence ministry in Beijing did not respond to requests for comment.
Wang Xudong, a satellite adviser to the central government, said the system was needed for the nation's defence.
"It's a necessary for China to boost its missile capability because the PLA's weapons are weaker than the US' shields, which are deployed everywhere in the world," Wang said.
The Pentagon has dubbed the Chinese vehicle WU-14.
Media reports in the US in June said Washington was funding the further development of a hypersonic missile programme amid concerns over China's research.
A US-based news website, the Washington Free Beacon, reported on this month's test on Tuesday, quoting unnamed American government officials.
Satellite expert Wang said China had a military disadvantage to the US because current technology meant Chinese missiles had to be fired from the mainland itself and could easily be intercepted.
"The US has sophisticated intelligence to routinely monitor the PLA's military development, but China doesn't have any overseas military bases," Wang said.
"All missiles launched by the PLA, if there was a military conflict, would be intercepted by the US' defence systems before entering the atmosphere."
Professor Arthur Ding Shu-fan, the secretary general of the Taipei-based Chinese Council of Advanced Policy Studies, said if Beijing successfully developed the vehicle, existing US missile defence systems might be rendered obsolete. "The WU-14 will become China's global strike weapon that would cause a great threat and challenges to the US."
A hypersonic expert told the South China Morning Post in January that China had more than 100 teams from leading research institutes and universities involved in the project.
"Developing [the vehicle] could definitely help China enhance its military deterrence, but Beijing will also stick to a no-first use nuclear doctrine," Beijing-based military expert Li Jie said.
Military spending topped US$145 billion in China last year, prompting fear and unease among many of its neighbours.
Correction: A previous version of this article misstated that the two hypersonic vehicle tests had failed. The first test was declared successful, but the second was not.