Huge op hits al Qaeda strongholds

• At least 30 militants have been killed, official says
• Predawn strikes hit al Qaeda in southern Yemen
• A U.S. drone attack is suspected, but the official won't confirm it
• Other officials express frustration, suspicion at lack of details

(CNN) -- An operation targeting al Qaeda in the Arabian Peninsula is under way in Abyan and Shabwa, Yemen, a high-level Yemeni government official who is being briefed on the strikes told CNN on Monday.

The official said that the scale of the strikes against AQAP is "massive and unprecedented" and that at least 30 militants have been killed. The operation involved Yemeni commandos who are now "going after high-level AQAP targets," the official said.

A day earlier, suspected drone strikes targeted al Qaeda fighters in Yemen for the second time in two days, killing "at least a dozen," the government official said.

The predawn strikes targeted a mountain ridge in the southern province of Abyan, the official said. It's the same area where scores of followers of al Qaeda in the Arabian Peninsula had gathered recently to hear from Nasir al-Wuhayshi, the head of the terrorist network's Yemeni branch and the global organization's "crown prince," the official said.

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Ayman al-Zawahiri is the leader of al Qaeda. A reward up to $25 million has been offered by the U.S. government. Click through to see men allegedly plotting, directing and, in some cases, carrying out acts of terror around the world.

Nasir al Wuhayshi is leader of al Qaeda in the Arabian Peninsula, known as AQAP.

Ibrahim al Asiri is thought to be the chief bomb-maker for AQAP.

Ahmed Abdi Godane, also known as Mukhtar Abu Zubayr, is the leader of Al-Shabaab. A reward up to $7 million has been offered by the U.S. government.

Moktar Belmoktar was the leading figure of al Qaeda in the Islamic Maghreb. A reward up to $5 million has been offered by the U.S. government.

Abu Muhammad al Julani is the leader of al-Nusra Front in Syria. Very little is known about Julani beyond his leadership status.

Abu Bakr al-Baghdadi is the leader of Islamic State in Iraq. A reward up to $10 million has been offered by the U.S. government.

Sirajudin Haqqani is the leader of the Haqqani Network in Afghanistan. A reward up to $5 million has been offered by the U.S. government.

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"It's too early to tell how many militants were killed, but the number is at least a dozen," the official said. The targets included "foreign nationals," the official said, but he provided no details of what their nationalities were. Nor was it clear whether any high-value targets were among the dead and wounded, he said.

Yemen's state news agency SABA said three strikes targeted an al Qaeda training camp in the village of Wadi al Khila, about 450 kilometers (280 miles) south of the capital Sanaa. The fighters were "preparing to launch attacks against Yemeni and foreign interests in the area," according to a statement from the country's Supreme Security Committee.

"These strikes destroyed the training facility completely and killed both Yemeni and foreign members," it said.

The official said Sunday's raid was a joint U.S.-Yemeni operation. He would not confirm whether drones were used in the attack, but the United States is the only country known to have conducted drone strikes in Yemen -- and as a rule, U.S. officials don't comment on those strikes.

But the official said the area is so rugged and mountainous that Yemeni troops would have faced heavy losses in any ground assault. Al Qaeda operatives had fled to the area after a 2012 push by government troops, backed by the United States, he said.

The high-level official said it would take time to fully clarify the details of the weekend's strikes -- whether the raids targeted camps, vehicles on the move or both, the full death toll among the militants, and whether there were any civilian casualties. A Saturday drone strike in a neighboring province killed at least 10 suspected al Qaeda militants, but also killed three civilian day laborers.

But other Yemeni officials, who asked to remain anonymous as they are not authorized to speak to the media, said there was growing frustration within the government about the lack of clarity and expressed concern that some of the information being reported by the military may be propaganda.

"I'm worried this is an attempt to convince Yemenis that the U.S. and Yemen have turned a corner and are in the process of destroying AQAP," one of those other officials said. "At this hour, the numbers of militants being reported as being killed keeps changing, and we still aren't sure if any civilians have been killed or wounded in these strikes."

"Yemenis are smart enough to doubt initial reports of this type," he added. "If this does turn out to be exaggeration, it will make the people here trust their government even less than they do and fuel growing anger over the drone program."

The United States first used armed drones to pick off an al Qaeda operative in Yemen in 2002. Strikes on suspected al Qaeda figures resumed in 2009, with more than 100 reported since then, according to the New America Foundation, a U.S.-based think tank that tracks the raids.

Those strikes have killed somewhere between 700 and 1,000 people, including at least 81 civilians, the foundation says.

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Journalist Hakim Almasmari contributed to this report.