The US military has carried out airstrikes against leaders of al-Shabab fighters in Somalia, the Department of Defense announced. "US military forces conducted an operation in Somalia today against the al-Shabab network," Rear Adm. John Kirby, the Pentagon press secretary, said in a statement on Monday. “We are assessing the results of the operation and will provide additional information as and when appropriate," Kirby added. The US strikes come after Somalia's government forces regained control of a high security prison in the capital Mogadishu that was attacked Sunday by seven heavily armed suspected al-Shabab militants who attempted to free other extremists held there. Somali officials said all the attackers, three government soldiers and two civilians were killed on Sunday. Somalia has been the scene of clashes between government forces and al-Shabab fighters since 2006. Reports came out last month saying that the CIA has stepped up its monitoring of 12 countries with so-called “ungoverned spaces.” American officials have confirmed the identity of ten of the countries, and one is Somalia. The US military frequently conducts drone surveillance flights over Somalia, but airstrikes and ground raids are 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. US special forces have intermittently conducted raids and operations in the country as well, but the military has kept their activities secret. The al-Shabab fighters have been pushed out of Mogadishu and other major cities in Somalia by the African Union Mission in Somalia (AMISOM), which is made up of troops from Uganda, Burundi, Djibouti, Sierra Leone and Kenya. In October 2013, the Pentagon secretly deployed a small team of military “advisers” to Mogadishu to coordinate operations with AMISOM. The deployment marked the first time 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.