(CNN) -- Officials call the attack "massive and unprecedented."
At least 65 suspected terrorists killed. Assaults from both the ground and the sky. And elite, clandestine U.S. forces joining Yemeni commandos in targeting al Qaeda in the Arabian Peninsula -- considered the global terror group's most dangerous affiliate.
But what would make the raid in southern Yemen most significant is if it yielded a target who Americans and Yemenis have been looking for: Ibrahim al-Asiri, the group's chief bomb maker.
While U.S. officials said the operation didn't directly target him, al-Asiri is among those suspected to have been killed in the Sunday firefight, a high-level Yemeni government official told CNN.
According to two Saudi government officials, authorities have taken at least one body to Saudi Arabia for DNA testing. It is that of a Saudi-born militant from al Qaeda in the Arabian Peninsula, officials said, declining to say whether they believe it's al-Asiri.
DNA test results are not due for several days.
Who is al-Asiri?
Al-Asiri is the alleged mastermind of al Qaeda's most creative and disturbing explosive devices.
Alleged plots tied to him -- the so-called underwear bomber aboard a U.S.-bound jetliner in 2009 and printer bombs dispatched to America the next year aboard cargo planes -- almost worked.
He even sacrificed his younger brother, a suicide bomber, in a failed attempt to kill Saudi Arabia's head of counterterrorism in 2009.
Al-Asiri constructed a bomb like none al Qaeda had produced before: a device designed to be inserted into the rectum of a suicide bomber containing around 100 grams of PETN, a difficult-to-detect white powdery explosive.
Only his brother was killed.
What led up to this raid?
A video and a threat.
A recently released video showed about 100 suspected al Qaeda members meeting at a training camp in Yemen.
In the middle of the video, the man known as al Qaeda's crown prince, Nasir al-Wuhayshi, appears brazenly out in the open, greeting followers.
Al-Wuhayshi is the No. 2 leader of al Qaeda globally and the head of AQAP.
In a speech to the group, he makes it clear that he's going after the United States, saying: "We must eliminate the cross. ... The bearer of the cross is America!"
Retired U.S. Gen. Richard Myers said the video raised serious concerns.
"If that's true, then you have to go after them," Myers told CNN's "The Situation Room." "I don't think that's sufficient in the end to defeat al Qaeda, but I think it's important that we go after them in this case."
What role did the U.S. play?
A U.S. official who spoke on the condition of anonymity said no Americans took part in combat on the ground, but U.S. forces did wear night vision gear and flew Yemeni forces to a remote, mountainous spot in southern Yemen.
The Yemeni helicopters that the U.S. personnel flew were Russian-made, which helped to minimize the American footprint during the operation.
And CIA drones are suspected to have targeted al Qaeda fighters, weapons locations and a training camp.
Pentagon spokesman Adm. John Kirby declined to detail the U.S. involvement in the operation, though he did highlight the partnership with Yemen.
"We continue to work with the Yemeni government and the Yemeni armed forces to help them improve their counterterrorism capabilities inside the country," Kirby said. "That work continues, and it will continue."
CNN's Paul Cruickshank, Nic Robertson, Tim Lister and Greg Botelho contributed to this report.