Updated

A U.S. drone targeted the leader of the Al Qaeda-linked al-Shabaab group in a strike in southern Somalia on Monday, Defense officials confirmed.

Pentagon Press Secretary John Kirby confirmed the strike on Tuesday, though he could not say whether it was successful.

"This operation was a direct strike against the Al Shabaab network, specifically against the group's leader," he said. "We are still assessing the results of the operation and we'll provide additional information when and if appropriate."

The strike was targeted at al-Shabaab leader Ahmed Abdi Godane.

A senior Somali official, speaking on condition of anonymity, also told The Associated Press that the drone targeted Godane as he left a meeting of the group's top leaders. The official told AP that intelligence indicated Godane "might have been killed along with other militants."

Godane, also known as Mukhtar Abu Zubeyr, is the group's spiritual leader under whose direction the Somali militants forged an alliance with Al Qaeda.

The official said that the strike took place in a forest near Sablale district, 105 miles south of Mogadishu, where the group trains its fighters. The governor of Somalia's Lower Shabelle region, Abdiqadir Mohamed Nor, told The Associated Press that as government and African Union forces were heading to a town in Sablale district, they heard something that sounded like an "earthquake" as drones struck al-Shabaab bases.

"There was an airstrike near Sablale, we saw something," Nor said.

After the U.S. strike Monday night, masked Islamic militants arrested dozens of residents suspected of spying for the U.S. and searched nearby homes, a resident said.

"Mass arrests just started, everyone is being detained," said Mohamed Ali, who lives in Sablale district. "They even searched nearby jungles and stopped the nomads transporting milk and grass to the towns for questioning."

The U.S. has carried out several airstrikes in Somalia recent years.

A U.S. missile strike in January killed a high-ranking intelligence officer for al-Shabab, and last October a vehicle carrying senior members of the group was hit in a U.S. strike that killed al-Shabab's top explosives expert.

The U.S. action comes after Somalia's government forces regained control of a high security prison in the capital that was attacked Sunday by seven heavily armed suspected Islamic militants who attempted to free other extremists held there. The Pentagon statement did not indicate whether the U.S. action was related to the prison attack.

Somali officials said all attackers, three government soldiers and two civilians were killed. Mogadishu's Godka Jilacow prison is an interrogation center for Somalia's intelligence agency, and many suspected militants are believed to be held in underground cells there.

The Somali rebel group al-Shabaab, which is linked to Al Qaeda, claimed responsibility for the attack that shattered a period of calm in Mogadishu after two decades of chaotic violence. The attack started when a suicide car bomber detonated an explosives-laden vehicle at the gate of the prison, followed by gunmen who fought their way into the prison.

It was al-Shabaab gunmen who attacked the upscale Westgate Mall in Nairobi, Kenya, with guns and grenades last September, killing at least 67 people. Al-Shabaab had threatened retaliation against Kenya for sending troops into Somalia against the extremists. Godane said the attack was carried out in retaliation for the West's support for Kenya's Somalia invasion and the "interest of their oil companies."

Al Shabaab is now mostly active in Somalia's rural regions, after being ousted from the capital by African Union forces in 2011. But the group is still able to launch lethal attacks -- often involving militants on suicide missions -- within Mogadishu, the seat of government.

Somali military officials last week launched a military operation to oust al-Shabab from its last remaining bases in the southern parts of Somalia.  However, on Saturday the town of Bulomarer, which is about 70 miles south of Mogadishu, was seized from militants after hours of fighting.

Fox News' Justin Fishel and The Associated Press contributed to this report.