The US has carried out a military operation against al-Shabab militants in Somalia, officials say.
The Pentagon is assessing the results of Monday’s operation before releasing details, a spokesman said.
However a US official quoted by the American media said “a senior al-Shabab operative” had been targeted.
The al-Qaeda-linked group lost control of Mogadishu to an African Union (AU) force in 2011 but still hold many southern and central areas.
“We are assessing the results of the operation and will provide additional information as and when appropriate,” Pentagon spokesman John F Kirby said in a statement.
The American action comes after al-Shabab rebels attacked a detention centre in Mogadishu on Sunday, in an apparent effort to free other militants detained there.
Somali officials said all of the attackers, as well as three government soldiers and two civilians, were killed.
The Pentagon and the US state department have supported the 22,000-member AU force that drove al-Shabab from their former strongholds in the capital and other urban centres.
The militants continue to carry out bombings and assassinations in the city.
Al-Shabab fighters want to overthrow the internationally supported Somali government and frequently attack government targets as well as neighbouring countries that provide troops to the AU force.
The group said it carried out last year’s attack on the Westgate mall in the Kenyan capital, Nairobi, in which at least 67 people were killed.