Both journalists suffered head injuries, and Woodruff also has broken bones. They were in stable condition following surgery at a U.S. military hospital in Iraq, and due to be evacuated to medical facilities in Germany, probably overnight, said ABC News President David Westin.
"We take this as good news, but the next few days will be critical," Westin said.
Woodruff and Doug Vogt, an award-winning cameraman, were embedded with the 4th Infantry Division and traveling in a convoy with U.S. and Iraqi troops near Taji, about 12 miles north of Baghdad.
They were wearing body armor and helmets but were standing up in the hatch of the mechanized vehicle when the device exploded, exposing them to shrapnel. An Iraqi solder was also hurt in the explosion.
ABC said the men were in the Iraqi vehicle — considered less secure than U.S. military equipment — to get the perspective of the Iraqi military. They were aware the Iraqi forces are the frequent targets of insurgent attacks, the network said.
"If you're going to cover the Iraqi military, you have to go with them, you have to see how they live," said ABC News correspondent Martha Raddatz, reporting on the attack on ABC's "This Week" Sunday.
The U.S. military confirmed that Woodruff and Vogt were injured in the midday attack and said an investigation is under way.
CBS News correspondent Lara Logan, who has covered Iraq, said the Taji area is considered particularly dangerous because it was the site of one of Saddam Hussein's munitions dumps. Many of the explosives are believed to have gotten into the hands of insurgents, she said.
"I admire Bob for going with the Iraqis," said Logan, who was blown 12 feet in the air by an explosion while with the U.S. military in Afghanistan in 2003. "It's important to hear their story and to experience it from their point of view. He did the right thing."
Improvised explosives are the simplest and deadliest weapon in the insurgents' arsenal, reports CBS News correspondent Elizabeth Palmer. Made of old artillery shells or stolen explosives and hidden on the roadside, they can be triggered by anything from trip wires to cell phones.
This year, the U.S. military will spend $3.5 billion to protect soldiers with better training, and technology like robots that can find improvised explosives and detonate them, Palmer reports. But by the end of last year, improvised explosives were killing two out of every three American soldiers who died in combat in Iraq.
It was another dose of bad news for ABC News, still recovering from the cancer death of Peter Jennings in August. Woodruff, 44, assumed Jennings' old job anchoring "World News Tonight" with Elizabeth Vargas earlier this month.
Setting the broadcast aside from its network rivals, ABC usually stations one of the anchors in a New York studio while the other is doing reports from the field. Woodruff spent three days in Israel last week reporting on the Palestinian elections, and was to have been in Iraq through the State of the Union address on Tuesday, according to ABC.
Woodruff, a father of four, has been at ABC News since 1996. He grew up in Michigan and became a corporate lawyer in New York, but changed fields soon after a stint teaching law in Beijing in 1989 and helping CBS News during the Tiananmen Square uprising.
Vogt, 46, is a three-time Emmy award winning cameraman from Canada who has spent the last 20 years based in Europe covering global events for CBC, BBC and now exclusively for ABC News. He lives in Aix-en-Provence, France.
Vogt was recently in another convoy in which someone was killed by another improvised explosive device but Vogt wasn't injured.
"They've covered all the wars, the hot spots," said ABC News' Jim Sciutto, who is covering the war in Iraq. "The best we have with Doug. He's the cameraman we all request when we go to the field because he's so good, a fantastic eye. He's won so many awards for ABC."
On CBS' "Face the Nation" Sunday, anchor Bob Schieffer abandoned his commentary to wish Woodruff and Vogt well. "It just hit us all like a lightning bolt because we've all been there," he later told The Associated Press.
NBC "Nightly News" anchor Brian Williams said he had been in touch with Woodruff's family and is praying for the families of both men.
"There is no way to cover the story in Iraq without exposure to danger," he said.
Dozens of journalists have been injured, killed or kidnapped in Iraq since the 2003 U.S.-led invasion that toppled Saddam Hussein. Increasingly, the local media in Iraq have paid the heaviest price. Logan reports two out of every three journalists killed are Iraqi.
Jill Carroll, a freelance reporter for The Christian Science Monitor, was kidnapped by gunmen Jan. 7. She was among 250 foreigners who had been taken captive in the country since the U.S. invasion; at least 39 of those foreigners were killed.
The most visible among the U.S. TV reporters was David Bloom of NBC News, who died from an apparent blood clot while traveling south of Baghdad on April 6, 2003.
The Blooms and Woodruffs were known to be close friends, and when NBC News executives had to tell Bloom's widow that her husband had died, they made sure Lee Woodruff was there to offer support.