STORY HIGHLIGHTS
- It was one of two U.S. special operations forces raids in Africa revealed Saturday
- The Navy SEALs had to withdraw because they came under fire
- Al-Shabaab has claimed responsibility for last month's Kenya mall attack
- Its stronghold is south-central Somalia
Washington (CNN) -- U.S. Navy SEALs entered the southern Somalia stronghold of Al-Shabaab, the group behind last month's Kenyan mall attack, in a mission targeting one of its leaders -- but caught in a firefight, the team had to withdraw before confirming whether its target was killed, a senior U.S. official said Saturday.
The raid occurred Friday, a Pentagon spokesman said, deep inside the area of Somalia controlled by Al-Shabaab, an al Qaeda subsidiary and U.S.-designated terrorist group intent on turning Somalia into a fundamentalist Islamic state.
It was one of two U.S. military operations in Africa revealed by U.S. officials Saturday. The other was a raid by U.S. special operations forces in Libya that happened Saturday and resulted in the capture of Abu Anas al Libi, a key al Qaeda operative wanted for his role in the bombings of U.S. embassies in Africa in 1998.
After coming under fire, the SEAL team in Somalia had to withdraw. The team made the "prudent decision" to withdraw rather than engage in further combat, the senior U.S. official said.
The identity of the targeted Al-Shabaab member wasn't known. Pentagon spokesman George Little said the operation was against a "known Al-Shabaab terrorist" but declined to provide more details; a second U.S. official said it was a "high-value Al-Shabaab terrorist leader."
The operation was aimed at capturing the Al-Shabaab target, the second U.S. official said.
No U.S. personnel were hurt or killed, the second official said, adding the U.S. team "took all necessary precautions to avoid civilian casualties" in the operation but did inflict some Al-Shabaab casualties.
Al-Shabaab claimed responsibility for the September 21 attack on a Nairobi, Kenya, mall that left 67 people dead. The United States has designated Al-Shabaab a terrorist organization.
The group is a subsidiary of al Qaeda, CNN National Security Analyst Peter Bergen says. It has a relationship with al Qaeda going back several years and last year formally announced a merger of the two groups.
Bergen: How Al-Shabaab picks its targets

Relatives of Johnny Mutinda Musango, 48, weep after identifying his body at the city morgue in Nairobi, Kenya, on Tuesday, September 24. Musango was one of the victims of the Westgate Mall hostage siege. Kenyan security forces were still combing the mall on the fourth day of the siege by al Qaeda-linked terrorists.
Ann Gakii reacts at the Nairobi City Mortuary after identifying the body of her father, who was killed in the mall attack on Saturday.
A Kenyan soldier runs through a corridor on an upper floor at the Westgate Shopping Mall in Nairobi, Kenya, on September 24, shortly before an explosion was heard. Sounds of heavy gunfire erupted from the mall Tuesday, even as authorities said they had the building under their control. But four days after Al-Shabaab terrorists stormed the swanky mall, several gunmen -- including snipers -- were still inside, two senior officials said.
Kenyan Defense Forces walk near the mall on Monday, September 23.
Kenyan Defense Forces leave the mall on September 23.
Stephen, center, is comforted by relatives as he waits for the post mortem exam of his father, who was killed in Saturday's attack at the mall.
A Kenyan police officer guards the entrance of a building near the mall on September 23.
A Kenyan security officer takes cover as gunfire and explosions are heard from the mall on September 23.
Heavy smoke rises from the Westgate Shopping Mall on September 23.
Medics take cover behind a tree as gunfire and explosions are heard from the Westgate Mall on September 23.
A Kenyan police security officer runs for cover as heavy smoke rises from the mall on September 23.
A paramedic runs for cover outside the mall on September 23.
People run for cover outside the mall after heavy shooting started on September 23.
Kenyan security forces crouch behind a wall outside the mall on September 23.
Soldiers take cover after gunfire near the mall on September 23.
Kenyan paramilitary police officers patrol the area near the mall on Sunday, September 22.
Soldiers from the Kenya Defense Forces arrive outside the Westgate Mall on September 22.
A woman shields a baby as a soldier stands guard inside the Westgate Mall on Saturday, September 21.
A rescue worker helps a child outside the mall.
People who had been hiding inside the mall during the gunfire flee the scene.
An armed official takes a shooting position inside the mall.
An armed official crouches on September 21.
Bodies lie on the ground inside the mall.
Men help a wounded woman outside the mall.
Officials carry an injured man in the mall.
Soldiers move up stairs inside the Westgate Mall.
Armed police leave after entering the mall. At least one suspect has been killed, a government official said. Police have said another suspected gunman has been detained at a Nairobi hospital.
Armed police take cover behind escalators as smoke fills the air. Witnesses say tear gas was thrown in the corridors.
A woman who had been hiding during the attack runs for cover after armed police enter the mall.
A body is seen on the floor inside the smoke-filled four-story mall.
An injured person is helped on arrival at the Aga Khan Hospital in Nairobi after the attack at the upscale mall.
A soldier directs people up a stairway inside the Westgate on September 21.
An injured man is wheeled into the Aga Khan Hospital in Nairobi.
People run from the Westgate Mall.
A Kenyan woman is helped to safety after the masked gunmen stormed the upscale mall and sprayed gunfire on shoppers and staff.
Crowds gather outside the upscale shopping mall. The interior ministry urges Kenyans to keep off the roads near the mall so police can ensure everyone inside has been evacuated to safety.
A policeman carries a baby to safety. Authorities said multiple shooters were at the scene.
Bodies lie outside the shopping mall.
A security officer helps a wounded woman outside.
Elaine Dang of San Diego is helped to safety after the attack. The military asked local media not to televise anything live because the gunmen are watching the screens in the mall.
Paramedics treat an injured man outside the mall.
Medical personnel carry a body away.
A body lies outside the mall. Gunmen shot people outside the mall as they entered it
A woman is pulled by a shopping cart to an ambulance.
A wounded man is escorted outside the mall.
A police officer carries a baby as people keep low and run to safety. Crowds dashed down the streets as soldiers in military fatigues, guns cocked, crawled under cars to get closer to the mall.
People run away from the scene.
Armed Kenyan forces take position to secure the area around the shopping mall as ambulances move in to carry the injured.
A woman reacts after she is rescued from the mall.
A couple flee the area. As night fell, authorities said they had cornered the gunmen in the mall.
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
Kenya mall attack
HIDE CAPTION
Photos: Kenya mall attack
Al-Shabaab hopes to turn Somalia into a fundamentalist Islamic state, according to the Council on Foreign Relations, but recently its aims have turned outward.
In 2010, Al-Shabaab claimed responsibility for two suicide bombings carried out in Kampala, Uganda, amid crowds of soccer fans watching televised screenings of the World Cup final. The bombings left 74 people dead.
The group said at the time the attacks were retaliation for Ugandan participation in the African Union Mission in Somalia (AMISOM). One AMISOM goal is to support Somalian government forces in cracking down on Al-Shabaab.
Al-Shabaab has also mounted many smaller attacks against targets in Kenya, hurling hand grenades into nightclubs, restaurants and schools. The group has also kidnapped tourists and aid workers.
South-central Somalia is where most of the group's foreign fighters and leaders have lived since Somali and African forces pushed them out of the capital, Mogadishu, two years ago.
The group in south-central Somalia has been increasingly squeezed as Kenyan forces move up from the south and African Union forces come down from Mogadishu.
In claiming responsibility for the mall attack, Al-Shabaab said it was in retaliation for Kenya's involvement in the African Union effort against the group.
CNN's Nima Elbagir contributed to this report from Nairobi, Kenya.