Viewers of China Central Television got an unusual glimpse last month of that nation’s offensive cyber-capabilities: A video clip showed a military computer program on which an unseen user selects a “target” — in this case, a Falun Gong website based in Alabama — and hits a button labeled “attack.”

The video amounted to just six seconds in a state media documentary called “The Cyber Storm Has Arrived!” But it offered an uncommonly candid depiction of cyber-weaponry developed by a country that is routinely accused of mounting attacks and just as routinely issues fervent denials.

Later in the documentary, Col. Du Wenlong, a researcher at China’s top military research institute, argues that the country’s ability to attack and to defend its networks “must be interwoven.” He adds, “To keep up with the pace of virtual technology, we must increase our fighting ability.”

For more than a decade, experts say, China has had a cyber-warfare capability, and in recent years, the nation has seemed intent on developing it — especially now that the United States has launched a Cyber Command to coordinate the military’s offensive and defensive capabilities.

The documentary featuring the video clip includes images of the Pentagon, the White House and U.S. jets bombing targets as the narrator describes China as behind its adversaries in developing cyber-capabilities. Du describes several types of attacks that might be deployed in cyber-warfare, including “logic bombs,” software implanted in an adversary’s network that later can be triggered to cause crucial systems to crash.

Western experts who viewed the clip, first reported by the Epoch Times, a news service affiliated with the Falun Gong, said the military computer program featured in the video was not especially sophisticated and probably does not represent the state-of-the-art of Chinese cyber-capabilities. Yet they were struck by what appeared to be the first and most public indication from a government source that China has the ability and the intention to hit adversaries, even when their computer servers are based in other countries.

“Their official line is they’re innocent, ‘Why are you blaming us?’” said James Lewis, director of the Center for Strategic and International Studies’ technology and public policy program. In the clip, he said, “they were caught with their pants down.”

Chinese officials have long insisted that their own national laws prohibit any disruption of computer networks. Yet when major cyber-attacks have happened — against Google, Lockheed Martin, the Dalai Lama, the office of the German chancellor — U.S. analysts and some international authorities have blamed China.

Between 1999 and 2001, China began cracking down on Falun Gong activists, whom they saw as a potential source of unrest in the country, according to a 2002 Rand study. A spiritual sect, Falun Gong was banned in 1999 by the Chinese government, which declared it an “evil cult.” Since then, some of its followers have been killed and thousands detained amid a decadelong crackdown.

The Chinese government has sent several members to prison for disseminating Falun Gong material on the Internet and routinely blocked access to Falun Gong Web sites, including “mirror” sites hosted on servers around the world.

The Internet address that appeared on the screen during the “attack” sequence in the video is registered to the University of Alabama at Birmingham. Officials there said that a student in 2001 hosted a Falun Gong Web site on the university server linked to that address but that the site was removed soon after.

Wang Baodong, a spokesman for the Chinese Embassy in Washington, declined to elaborate on the images shown in the video but said: “It’s no secret that Falun Gong and its subordinate institutions have been intensifying their subversive efforts against China in cyberspace. And China has every legitimate right to take action against such harmful activities to defend its national security interests.”

Erping Zhang, a spokesman for the Falun Gong Information Center in New York, said: “We have been experiencing constant hacking from China for many years. We knew it was being done, but we never knew it was to this extent with actual military resources devoted to attacking us. And to have that so openly admitted to the public on a CCTV report. It’s surprising and appalling.”

Zhang said Falun Gong has “no special activity in Alabama” not conducted elsewhere, but the group did have a second website that was hosted by a regional affiliate in the state. On the clip of the military attack program, the website for this group was listed as a possible target.

“The fact that they would even target a small club in Alabama gives us an idea how seriously they take the cyber-warfare,” Zhang said.

The documentary aired two days after the July release of the Pentagon’s first cyber-strategy, which focuses on defense but which China has interpreted as a sign of cyberspace aggression.