When Israeli commandos attacked the so-called Freedom Flotilla, both sides were well armed — with video cameras — and both sides have released a blizzard of video clips as evidence that the other side was the aggressor in the conflict on Monday, which left nine activists dead.

Once again, the political power of the moving picture is on display, as it was last year when a video showing the death of a young protester in Iran, Neda Agha-Soltan, became a symbol of resistance in that country.

The flotilla videos have proved a popular draw online, with one from the Israel Defense Forces attracting more than 600,000 views on YouTube. Scenes from both perspectives have been shown in a continuous loop on television news programs all over the world, stirring public outrage.

But what is missing so far from the flotilla clips on both sides is context: it is difficult to establish the sequence of events or, more simply, to determine who attacked first. The videos have made it all the more murky.

“On a matter like this, public opinion is awfully important, in terms of determining which image is really going to last,” said Jim Hoge, the editor of Foreign Affairs, who observed that there had been a gradual increase in the use of video clips to bear witness and shape opinion.

“First it was people in crowds with mobile phones,” he said, speaking about the Neda video. “Now, as is so often the case, governments catch up and begin to use the tools for their own purposes.”

Activists do, too. The flotilla’s organizers, from Insani Yardim Vakfi, the Free Gaza Movement and other groups, were Webcasting live from the open seas as the confrontation started, using the services of Livestream, a New York-based company that hosts free Webcasts.

The organizers “chose to make their trip to Gaza a media event,” said Max Haot, Livestream’s co-founder. Aboard the ship was a “full multicamera production,” he said, uplinked to the Internet and to a satellite that allowed news channels to rebroadcast live pictures of the raid in progress.

The Israeli military has used its YouTube channel to post nearly 20 videos, sometimes enhanced by graphics and captions, trying to show that its soldiers were acting in self-defense.

Representatives of the Israeli military and the Free Gaza Movement did not respond to interview requests about their media operations on Tuesday.

Video images from the vessel, the Mavi Marmara, were viewed by a quarter of a million people on Livestream, Mr. Haot said, and after the attack they were watched by countless others on television. In one especially notable scene, Israeli soldiers could be seen hoisting their guns (just paint-ball guns, the Israelis said) in preparation for the raid.

In a matter of hours, the Israeli military was publishing videos of its own, showing the action from the perspective of its soldiers. In one video apparently filmed before the raid occurred, a military cameraman is standing next to a soldier who is addressing the flotilla and directing it to a port, seeking a peaceful outcome.

In a later video, the soldiers appear to come under attack from activists who wield metal poles and chairs, which was emphasized in the video with yellow circles added by Israeli producers. Another video claims to show weapons found on the ship, including slingshots and knives.

The videos try to bolster the case that the soldiers were acting in self-defense when they fired at the activists. In one clip, an activist appears to push a soldier off the vessel.

What is not clear is what stage of the attack the video portrayed. Many activists have said that the Israelis fired stun grenades and tear gas, injuring people on the deck, before the commandos made their descent, and that the activists were simply retaliating.

The YouTube clips are part of an aggressive effort by the Israeli military to better communicate its work to the public. The I.D.F. channel has counted about 10 million views since it was started in December 2008.

Supplementing the war of images by the two sides, journalists filed reports from the Mavi Marmara. In one live television report that circulated widely on YouTube, a reporter for Al Jazeera English, the English-language arm of the Arabic-language news network, was shown stating that the vessel was “raising a white flag to the Israeli Army” amid the attack, but despite that, “the Israeli Army is still shooting, still firing live munitions.”

Shooting could be heard in the background, but again context was lacking. Al Jazeera’s account was cited by bloggers as evidence that the Israelis had attacked without provocation, but that assertion was not borne out by the video.

The nonprofit group Reporters Without Borders said Tuesday that at least 15 journalists who were aboard the flotilla had been detained by Israel and had not made contact with their respective news outlets. Among them were journalists from the Kuwait News Agency, The Sydney Morning Herald and Al Jazeera.

“They were not allowed at all to speak, so to get the other side of the story, the eyewitness account was the only piece of information that we had,” Salah Negm, the director of news for Al Jazeera English, said in a telephone interview from Qatar.

The fact that the Mavi Marmara was able to keep streaming — and the networks were able to keep reporting — as shots were fired underscores the challenges that the authorities face in a digital age. The right-leaning Jerusalem Post reported that the Israelis had intended to “jam the signals” from the vessel and blocked cellphone traffic but could not stop satellite transmissions.

“Without an Israeli response, which came out later in the day and seemingly proved that the soldiers acted in self-defense, the media were full of one-sided reports based on Al Jazeera,” the newspaper stated. “What Israel needs to realize is that in today’s media world, every minute counts.”

The episode proved to be a challenge, too, for third parties like Livestream that provide the backbone for video viewing on the Internet. Mr. Haot said Livestream thought about whether to censor the live video but decided not to, having concluded that it was “a controversial but genuine humanitarian mission.”

Still, he said, he found himself thinking that his Internet start-up needed policies in place to handle live videos of conflicts in the future. “After the events unfolded,” he said, “I spent most of my Monday wondering if we had helped terrorists or a great humanitarian cause.”