DOHA, Qatar  “Our bureau in Cairo has been attacked.”

Phone calls and e-mail on Friday spread that short message through the Doha headquarters of Al Jazeera, the satellite news network. It was an ominous start to the day, made worse by the fact that the day before, three of the network’s staff members had been arrested and others had been harassed amid the continuing protests in Cairo, the Egyptian capital.

Still, the network’s nonstop live coverage rolled on unabated. Al Jazeera’s Arabic- and English-language coverage has provided a worldwide megaphone for the protests that have disrupted the Middle East, first in Tunisia and then Egypt  and to a lesser degree, Yemen, Jordan and Sudan.

Al Jazeera stands to benefit greatly from its protest coverage, a fact not lost on the network, which has been placing advertisements in major American newspapers. The live reports strengthen the network’s already tight grip on its Arabic-language viewing public, while bolstering its argument that cable and satellite distributors in the United States should make the English version available to American viewers.

A sense of mission  and of opportunity  permeates the Al Jazeera compound on the outskirts of Doha, where on Friday the televised cries of antigovernment protesters resounded through the hallways at all hours along with the ringing of cellphones and the shouts of news anchors. Staff members were well aware they faced stiff challenges  from opponents who wish Al Jazeera off the air and skeptics who doubt the objectivity of a network backed by the emir of Qatar.