Washington (CNN) The military has completed its after-action review of the controversial raid in Yemen in January, with several defense officials providing details of the findings to CNN Friday.

They described why the raid was launched, how the battle became so intense, what led to the death of a Navy SEAL and several civilians, and the usefulness of the intelligence gained.

The officials confirmed to CNN that the target was intelligence and not an al Qaeda leader, adding that the enemy did not know the SEAL team was coming, but said that once the US troops were detected an intense firefight broke out between the American personnel, al Qaeda members and armed tribal villagers. Here is what we know now about the operation.

Who ordered the raid?

President Donald Trump first learned of the plan the morning of Wednesday, January 25, days after he had been inaugurated, a White House official told CNN. James Mattis, Trump's new secretary of defense, had already approved the raid by the time Trump learned of it, the official added.

Michael Flynn, Trump's then-national security adviser, presented the President with a written memo about the planned raid in the morning and the two discussed it a number of times during the day, the official said. Trump then asked Flynn to arrange a meeting so he could solicit advice from Mattis and Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff.

Flynn, Dunford and Mattis laid out the scenario for Trump over dinner, explaining to the President -- who has no military experience -- that there were inherent risks with the mission. He then authorized the operation.

When did the planning start?

Legal experts sent it to the National Security Council at the White House on December 19, Trump Press Secretary Sean Spicer said last month.

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"Clearly, that was under the last administration," Spicer said. "On December 19, the plan was approved by the Department of Defense and recommended that it be moved ahead."

While some Obama aides dispute that the Pentagon ever approved the raid, and others maintain the administration okayed it all the way to the Oval Office, what is agreed on by everyone is that Obama himself never signed off.

Such situations are remarkably fluid based on daily intelligence and conditions on the ground. The military wanted to hold off until better conditions prevailed, which didn't occur before Obama left office.

What was the objective?

The Pentagon has called the mission an intelligence gathering operation aimed at improving the US government's understanding of Al Qaeda in the Arabian Peninsula and its relationship to various Yemeni tribal fighters.

"Our intention here was to improve our knowledge against this threat, a threat that poses a direct threat to us here in the homeland," Gen. Joseph Votel, who oversees US troops in the region, told the Senate Armed Services Committee Thursday

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The Pentagon considers al Qaeda in the Arabian Peninsula the terror organization's most capable franchise. It has exploited the civil war in Yemen to carve out a safe haven.

Some reports indicated that the raid was aimed at capturing or killing the leader of AQAP, Qassim al-Rimi, and one Capitol Hill source said that the mission was intended to capture a senior AQAP leader. But multiple US defense and military officials have strongly rejected that notion.

The SEAL team was prepared to snatch, grab and interrogate people, a defense official told CNN, but said the operational planners did not think extremely high-value targets were present at the compound.

Who carried it out?

The raid involved elite US Navy SEALs and Special Forces from the United Arab Emirates operating on the ground, according to officials from several countries.

The operation was considered relatively risky by military officials, particularly because US lacks nearby support troops like Special Operations enjoys in Iraq and Syria. In order to mitigate the risk, US Marines aboard the USS Makin Island in the Gulf of Aden were standing by to assist as a "quick reaction force," equipped with MV-22 Osprey tilt-rotor aircraft, Harrier jets and Cobra attack helicopters.

Surveillance drones flew over the site during the entirety of the raid, giving military planners updates on the mission.

How did the SEALs come under attack?

As the US-UAE combined force approached the al Qaeda-linked compound, the group was detected and an intense firefight broke out.

A defense official with first-hand knowledge of the after-action review raid said the al Qaeda and tribal forces present did not know the SEALs were coming when they entered Yemen, saying there was absolutely no indication that either the US or UAE forces were seen before they started moving in on their objective, adding that the SEALs had observed the area for some time before going in.

But the official noted that due to their living close to the frontline of the ongoing civil war in Yemen, the nearby local villagers were very suspicious and prepared to resist foreign military forces or Houthi rebels. As a result, the official continued, the men, women and even some of the younger people in the village were all armed.

The review found that as the SEALs moved in on the target compound, they were fired upon by al Qaeda fighters and a significant number of villagers soon joined the terror operatives in their battle with the SEAL team.

"We did not expect the whole village to grab their weapons and start firing at us," the official said.

During the gun battle, which featured small-arms fire, hand grenades and close air support strikes from the US aircraft, al Qaeda fighters and armed villagers -- including some female combatants -- took up firing positions on the roofs of nearby buildings and the US troops were prevented from moving.

They called in an airstrike against the buildings, which likely led to the civilian casualties, a US military official told CNN. The Marine Harrier jets and Cobra helicopters began carrying out close support airstrikes and multiple MV-22 Osprey aircraft from the Makin Island, officials said, were sent to rendezvous with the Navy SEALs when they came under intense fire.

"This was a very difficult operation where we had US service members who were pinned down and needed help to get out and that help was called in with airstrikes," US Navy Capt. Jeff Davis told reporters Friday.

When did the US suffer casualties?

US Navy SEAL William "Ryan" Owens was killed in the gun battle, receiving a fatal wound. Three additional US personnel were wounded and several others injured when their aircraft made a hard landing.

"We lost a lot on this operation. We lost a valued operator, we had people wounded, we caused civilian casualties, lost an expensive aircraft," Votel, who oversaw the after-action report, told a Senate hearing Thursday.

On the question of why the SEALs proceeded with the mission once they came under attack, the official with direct understanding of the review said: "We don't just stop because we get fired at."

He said Votel supported the SEAL team commander's decision to carry on with the mission.

"We believed it was worth the risk," said a separate US military official, who noted the operational commander on the ground in Yemen could have scrapped the mission at any time. "It's a military assault. There's going to be risk."

Who else suffered losses?

Votel said the military conducted a review that determined that between two and 12 civilians were killed as a result of the raid. Local Yemeni officials told CNN that the number was 13.

The London-based NGO Reprieve and a Sanaa-based human rights worker told CNN that at least 23 civilians were killed in the attack, however.

The US military estimates that 14 enemy fighters were also killed in the battle.

The civilian casualties were "caught up in aerial gunfire that was called in to assist US forces in contact against a determined enemy that included armed women firing from prepared fighting positions," US Central Command said in a statement.

"The villagers feel very terrified by what happened," Mohammed al-Qawli, head of Yemen's National Organization for Drone Victims, told CNN. "They can't believe what happened. They feel the world has let them down. Sadness hangs over the whole area."

Local reports also indicated that the 8-year-old daughter of US-born terrorist Anwar al-Awlaki was also killed.

What was gained?

The US raid team captured hard drives, cell phones and laptops containing over a terabyte of data, one US official said, describing the intelligence as containing information pertaining to AQAP safe havens, targets, tactics and training techniques.

In an early bid to highlight what was gathered, the military suffered an embarrassing moment when it released a terrorist training video uncovered on the raid only to realize it had been previously available online

But several US officials told CNN this month that the US is now taking action to locate and monitor hundreds of people or "contacts" found as part of the intelligence retrieved during the raid.

The government is also taking action to find and monitor these AQAP-linked individuals because of the threat they may pose to Europe, the officials added.

The official with knowledge of the raid's operational details said the military "absolutely believes" the intelligence obtained will help disrupt al Qaeda plots.

Why all the political fallout?

The raid was the first of Trump's presidency, and the fact that it resulted in the death of a SEAL, the wounding of three others, the killing of multiple civilians and the loss of a $70 million aircraft have raised questions about whether there was adequate planning, proper execution and due deliberation by Trump himself.

The commander in chief has been quick to declare it a success, using the platform of his joint address to Congress in February to make that case, aided by a touching moment when he singled out Owens' crying wife, Carryn, in the balcony.

"Ryan was a part of a highly successful raid that generated large amounts of vital intelligence that will lead to many more victories in the future against our enemies,' " Trump told her from the floor of the House.

The military has declined to weigh in on whether the raid was a "success" but has said that the raid accomplished what it was intended to.

"It was a military mission," Davis, the US military spokesman, said Friday. "It completed its objective, but it did so at a cost."

Members of Congress, however, have been among those more critical of the operation. Some have questioned whether it should have been authorized in the first place.

"When you have women and children killed, as you pointed out; loss of a $70 million aircraft; you do not capture anyone ... that mission is not a success," the Chairman of the Senate Armed Services Committee, Republican Arizona Sen. John McCain, told Votel Thursday. "But that happens in war."

Owens' father was critical of the raid, calling for an investigation into what happened.

The military has conducted several investigations and reviews into the operation per standard operating procedure anytime there are civilian casualties, lost aircraft or the death of US service members.

The only investigation that is still ongoing is the examination of the loss of the Osprey.

Following the after-action review, Votel told the Senate that no additional investigations were warranted.

"I am looking for indicators of incompetence, poor decision-making or bad judgment throughout all of this," Votel told the committee. "I was satisfied that none of those indicators that I identified to you were present."

As a result, he said: "I made the determination that there was no need for an additional investigation into this particular operation."