Still, there was little doubt that they provided more exhaustive coverage than anyone else.

“It’s clearly been more comprehensive, and they have more reporters in different parts of the country,” said Samer S. Shehata, a professor of Arab Studies at Georgetown University who was watching the day unfold on several different Arab satellite channels. “There is an urgency in their coverage that helps show the importance of these events.”

Al Jazeera has often been accused of playing a partisan role, applauding rebellious voices and anti-American movements across the Middle East. On Friday, its anchors were careful to present opposing points of view, citing the Egyptian official media and airing interviews with figures close to the government, including Mustafa al-Fiqi, the chair of the foreign relations committee in the Egyptian Parliament.

After quoting wire service reports that the Foreign Ministry had been engulfed by demonstrators, it followed up with denials from Egyptian officials. A string of analysts appeared on screen or over the phone, including a former American ambassador to Egypt.

But the channel also pointed out the Egyptian government’s clumsy efforts to stop state-run news media from reporting on the violence. “Some of Egypt’s most prominent news anchors have actually, in the words of official statements, been put on vacation,” said a reporter on Al Jazeera’s English-language channel, which is run separately from the main Arabic news channel.

Both the Arabic and the English channel juxtaposed images in ways that undermined the government’s official messages.

At one point, the screen was split. On one side was live video of a police van that had been set on fire by protesters defying a curfew, with the sounds of gunfire and explosions. On the other side was the scene being broadcast by state television: a quiet tableau of the night sky in downtown Cairo, with the message that a curfew had been imposed.

When Secretary of State Hillary Rodham Clinton responded to the events by urging the Egyptian authorities to stop blocking broadcasts, Al Jazeera showed her remarks live with simultaneous Arabic translation, but also in a split screen, so as to contrast the language of diplomats with the reality of the streets. On the other side, the screen showed the dark, still-smoky streets of Cairo, where protesters were violating the government curfew.