‘‘We are assessing the results of the operation and will provide additional information as and when appropriate,’’ Rear Admiral John Kirby, the Pentagon press secretary, said in a statement late Monday.

Journalists in Somalia reported that suspected US drones fired missiles near the port city of Barawe, a stronghold for al-Shabab. In a rare acknowledgment of its clandestine military activities in Somalia, the Pentagon said it had conducted a counterterrorism operation there but gave no details.

WASHINGTON — The US military carried out a counterterrorism strike Monday against leaders of the militant group al-Shabab in Somalia, Pentagon officials said, although it was unclear whether the operation was successful.


The Pentagon statement did not say whether the operation was limited to drone strikes or whether US commandos had been present on the ground.

Nearly one year ago, on Oct. 5, Navy SEALs raided a seaside house in Barawe in an attempt to capture Abdulkadir Mohamed Abdulkadir, a Kenyan native and senior al-Shabab commander. That raid sparked a gunfight but was unsuccessful; US officials said the SEALs withdrew because the risk of harming bystanders had become too great.

The Obama administration has since posted a $3 million reward for information leading to Abdulkadir’s arrest or capture. A State Department bounty notice describes him as being about 35 years old, with a thick mustache and three missing fingers on his left hand.

The US government’s Voice of America news service, which broadcasts programs to Somalia, reported that a target of the attack may have been the alleged mastermind of al-Shabab’s attack on an upscale shopping mall in Nairobi, Kenya, in September 2013. That individual, Mukhtar Abu Zubeyr, also known as Godane, has emerged in recent years as the primary leader of al-Shabab, which means ‘‘the youth’’ in Arabic. The group has ties to Al Qaeda.


Voice of America, citing militants and African Union security sources in Somalia, reported that Godane was in the vicinity of the attack, but his fate was unknown. The broadcaster’s report could not be independently verified.

The US military frequently conducts drone surveillance flights over Somalia, but airstrikes and ground raids are relatively uncommon.

The Pentagon has a large drone base at Camp Lemonnier in Djibouti, which borders Somalia on the Horn of Africa. The US military also flies surveillance drones over Somalia from a base in Ethiopia.

The Pentagon quietly deployed a small team of advisers to Mogadishu, the capital of Somalia, in October 2013 to coordinate operations with African troops fighting to wrest control of the country from al-Shabab.

The deployment marked the first time regular US troops have been stationed in the war-ravaged country since 1993, when two helicopters were shot down and 18 Americans were killed in the ‘‘Black Hawk Down’’ disaster.

US commandos have intermittently conducted raids and operations in the country as well, but the military has kept their activities cloaked in secrecy.