Four people, including a U.S. soldier and two members of a CBS News crew, were killed Monday when a bomb ripped through the U.S. military convoy in which they were traveling.

CBS News crew Kimberly Dozier, Paul Douglas (C) and James Brolan were victims of an insurgent attack. [CBS]

CBS said cameraman Paul Douglas, 48, and sound tech James Brolan, 42, were killed in the blast. Both were British and based in London, the network said.

The U.S. military said a U.S. soldier and an Iraqi contractor also were killed in the attack on their convoy.

Six U.S. soldiers and CBS correspondent Kimberly Dozier were wounded in the attack, the military said.

The attack came as the convoy passed through Tahariyat Square, just across the river from the Green Zone, around 10:30 a.m. Monday (3 a.m. ET).

The convoy victims were among at least 50 people killed in insurgent attacks in Iraq on Monday.

The CBS team -- which was embedded with the 4th Brigade Combat Team, 4th Infantry Division -- was reporting from outside their Humvee and they were believed to have been wearing protective gear when the blast went off, according to CBS.

Zalmay Khalilzad, the U.S. ambassador to Iraq, said he was "shocked and saddened" by what he called a "savage attack" on the journalists.

"The terrorists who committed this evil crime have shown themselves for who they are," he said in a statement issued late Monday. "They do not want the world to see the truth of what is happening in Iraq, where a determined people are fighting for freedom and liberty. That story must and will be told."

Dozier spoke of dangers

Dozier, 39, suffered serious injuries and underwent surgery at a U.S. military hospital in Baghdad.

She is in critical condition, but doctors are cautiously optimistic about her prognosis, the network said.

Douglas had risked his life covering international conflicts for CBS since the early 1990s, including Iraq, Afghanistan, Pakistan, Rwanda and Bosnia, according to CBS News. He is survived by his wife, two daughters and three grandchildren.

Brolan was a freelancer who worked with CBS News in Baghdad and Afghanistan in the past year. He also shared an award with the network for its coverage of last year's deadly earthquake in Pakistan. He leaves a wife and two children.

In a written statement, his family said Brolan "had a natural way with people and was always in demand as the person to go with to the world's trouble spots."

"James was the best dad, the best husband and the best mate to be with in a tight spot out in the field," they said.

Dozier has reported from Baghdad since 2003. She is based in Jerusalem.

"This is a devastating loss for CBS News," said Sean McManus, president of CBS News and Sports, in a statement on the network's Web site. "Kimberly, Paul and James were veterans of war coverage who proved their bravery and dedication every single day. They always volunteered for dangerous assignments and were invaluable in our attempt to report the news to the American public."

Speaking on CNN's "Reliable Sources" in November 2004, Dozier described the dangers of trying to talk to ordinary Iraqis in Baghdad.

"The last time I tried to do that, to go to someone's home and sit down with that man and say, 'Are you thinking about leaving Iraq or staying?' the moment he saw me, blonde hair and my two armored vehicles ... he turned white," Dozier said.

"It means I can't go out and hunt a story. I'm having to wait for it to come to me, or I'm having to train Iraqi translators to go out and be my eyes, be my ears, ask the questions that I would ask if I could."

Earlier this year, ABC News anchor Bob Woodruff and cameraman Doug Vogt were seriously wounded when the U.S.-Iraqi military convoy in which they were embedded was hit by a roadside bomb near Taji, north of Baghdad.

Between 94 and 120 journalists and media support staff -- including drivers and translators -- have been killed in Iraq since the war began in 2003, according to journalists' organizations and watchdog groups.